The figures in my renders always have some shadows like this, it looks like a dark line. I tried change the angle of lights, the map sides, but still got this things. Anyone can tell me how to get rid of this things?

Hi, You aren`t getting an even enough overall light set-up. You should add a few more lights, or get the Global light sets in free stuff. "Global" as a keyword gives what you need. Come out of the dark and into the light! Mark

Normally, shadows & shading are a good thing. It's what gives the viewer visual cues as to shape (is it a disc or a sphere) and setting (day/night, int/ext, etc.) That said, to eliminate shadows, place one light on the camera's axis. (Image will be lit flat like a bad flash photo) (wow, really strong deja vu)