I use Media Pro for several years, I would like to move to Lightroom.
Is it possible to transfer my catalogs without losing all attributes.
IIRC Media Pro can do some image adjustments; to preserve those you'd probably have to export those images from Media Pro.
If you can write metadata into image files from Media Pro then Lr will import that, and you can use keywords to transfer otherwise non-transferable data like ratings and such.
You might wanna check Lightroom Solutions – John Beardsworth site to see if he has a plugin to make this easier, or maybe a script (I think he does custom ones as well). I think I ran across something he had on Media Pro before Phase One acquired it, but it's been quite a while.