Hi DeanLoganBH,

Thanks for ur answare however my problem is littlebit different. According to u if i set the min and max value manually the axis value units are showing perfectly but the column draw region are not in properly. please have a look to the attached screen shot of the chat and the sample code as well.

<?xml version="1.0" encoding="utf-8"?>

<mx:Application xmlns:mx="http://www.adobe.com/2006/mxml" layout="absolute" minWidth="955" minHeight="600"

                                        creationComplete="application1_creationCompleteHandler(event)" xmlns:local="*">

<mx:Script>

                    <![CDATA[

                              import mx.charts.AxisRenderer;

                              import mx.charts.ColumnChart;

                              import mx.charts.LinearAxis;

                              import mx.charts.series.ColumnSeries;

                              import mx.charts.series.ColumnSet;

                              import mx.charts.series.LineSeries;

                              import mx.collections.ArrayCollection;

                              import mx.events.FlexEvent;

                              [Bindable] public var SMITH:ArrayCollection = new ArrayCollection([{date:10, close:41.87, open: 30},

                                        {date:20, close:45.74, open: 40},

                                        {date:30, close:42.77, open: 60},

                                        {date:40, close:48.06, open: 50}]);

                              [Bindable] public var DECKER:ArrayCollection = new ArrayCollection([{date:10, close:157.59},

                                        {date:20, close:160.3},

                                        {date:30, close:150.71},

                                        {date:40, close:156.88},]);

                              private var myChart:ColumnChart = new ColumnChart();

                              protected function application1_creationCompleteHandler(event:FlexEvent):void

                              {

  // VERTICAL AXIS

                                         var verticalAxisLeft:LinearAxis = new LinearAxis();

                                        verticalAxisLeft.autoAdjust = true;

                                        verticalAxisLeft.minimum = 0;

                                        verticalAxisLeft.maximum = 120;

                                        var verticalAxisRight:LinearAxis = new LinearAxis();

                                        var verticalAxisRendererLeft:AxisRenderer = new AxisRenderer();

                                        var verticalAxisRendererRight:AxisRenderer = new AxisRenderer();

                                        verticalAxisRendererLeft.axis = verticalAxisLeft;

                                        verticalAxisRendererLeft.placement = 'left';

                                        verticalAxisRendererRight.axis = verticalAxisRight;

                                        verticalAxisRendererRight.placement  = 'right';

  // SERIES

                                        var newSeries:Array = new Array();

                                        var columnset:ColumnSet = new ColumnSet();

                                        columnset.type = 'stacked';

                                        var columnSeries:ColumnSeries = new ColumnSeries();

                                        columnSeries.dataProvider = SMITH;

                                        columnSeries.yField = "close";

                                        columnSeries.displayName = "SMITH_close";

                                        columnset.series.push(columnSeries);

                                        var columnSeries1:ColumnSeries = new ColumnSeries();

                                        columnSeries1.dataProvider = SMITH;

                                        columnSeries1.yField = "open";

                                        columnSeries1.displayName = "SMITH_open";

                                        columnset.series.push(columnSeries1);

                                        columnset.verticalAxis = verticalAxisLeft;

                                        newSeries.push(columnset);

                                         var lineSeries:LineSeries = new LineSeries();

                                        lineSeries.dataProvider = DECKER;

                                        lineSeries.yField = "close";

                                        lineSeries.verticalAxis = verticalAxisRight;

                                        lineSeries.displayName = "DECKER";

                                        newSeries.push(lineSeries);

                                        myChart.verticalAxisRenderers = [verticalAxisRendererLeft,verticalAxisRendererRight];

                                        myChart.series = newSeries;

                                        myChart.showDataTips = true;

                                        chartContainer.addChildAt(myChart, 0);

                              }

                    ]]>

</mx:Script>

<mx:Panel id="chartContainer" title="Column Chart With Multiple Axes">

                    <mx:Legend dataProvider="{myChart}"/>

</mx:Panel>

</mx:Application>

In the above image the tooltip display Smith_Close value is 41.87 however it's pillar vertical axis maped with value nearly  28. and the total value is 71 but it map with below 50 in vertical axis. which seems visually inconsistent.

Problem:- why the column set is not calculate min and max value automatically and scale the colums appropiatly  in case of custom axisrenderer however it is working fine default axis rendere.

Again the calculation of min max is little bit complex when my column set is containing more serieses and thereir value is varies in negative and positive side.

DeanLoganBH, if is there any point is not understandable please let me know..

Thanks in advance