I was following the FPS character tutorial.It was great 
But the tutorial didn’t over how to set animation also for the 3rd person character mesh.I was trying to assign existing animations from AnimStarterPack to that Mesh but it even doesn’t show up in “Animation” Dropdown list.So how can I assign existing animation data to animation blueprint?
Hi SasMaster,
The animations referenced in that tutorial are for first person only. Here’s a link to a great third person tutorial which also links animations for a third person character.
Here’s the link to the tutorial: - YouTube
Here’s a link to just the animations, if you want to try applying them to the third person in the current tutorial you are working on: A new, community-hosted Unreal Engine Wiki - Announcements - Epic Developer Community Forums
Yeah I know,but my question is why I can’t add animations from another model to that skeletal mesh?
The animations from the AnimationStartePack do not show up in the drop down menu because they are bound to a different (although very similar looking) mesh. In order to use these animations with the default third person Animation Blueprint you will need to retarget the animations as instructed here:
Oh,so with my question I exactly hit that new feature in 4.5? 
I may not be understanding your question, but the re-targeting feature has been available since UE4.3. This feature will allow you to bind the animations from Epic’s Animation Starter Pack to the original default 3rd Person Skeleton referenced in the tutorial which is what I thought you were trying to accomplish.
Here is animation retargeting system mentioned as new feature:
Yes, technically you are correct. The feature was officially announced with version 4.5, although it’s been available for use since 4.3.