How do I solve that problem

I'am at the very beginning of the making games. I'am trying to make a basic platform game. My problem is, when i set a falling animation to my character, character is running with falling animation, not with running animation. Sorry, if I can't explain my problem. And sory for my bad English.

EDIT

I set the gravity 50000, and problem is solved. But i want to know what is cause that.

You have made a mistake in events, next time consider posting your capx file.

Here is a good way to change animations for a platform character (screenshot from someone else's game):