Why does the leg bone move the whole body? I have a 3d model 



And when I move the Left Leg bone it works fine like this.



But when I move the Right leg bone I get this Problem



How can I solve this???

(Links are Images)
You are using vertex groups to bind armature to mesh : so you'll have to     


Delete the duplicated vertex groups 
Fix/reassign the needed ones ( Head, Body, Arm_L, Arm_R, Leg_R and Leg_L )
Use only one Armature modifier ( delete the others )