Draw line on cube ?

How I can draw on cube with mouse ?

To get mouse possition, but it get all points to draw 1 line.
How i can draw same lines in 1 cube with size ( 100, 100 , 1 ) ?

You could do this the same way as you leave a bullet hole texture.

Raycast from the mouse position, get the hit information where that ray hits the cube. Find the normal of that hit, and instantiate a plane with the texture of an ink dot at the hit position and rotated to the normal. Of course once you do this too many times, the draw calls and number of objects will slow everything down. As in the comments, you need to be more clear : what are you trying to do exactly? just paint a cube?

The closest I can think of to what you need is the above, or : Draw a line in game - Questions & Answers - Unity Discussions

Due to my intellect, it is not possible to draw a line to the cube. But it is possible for you to put a material so it could have the picture. In the picture you must draw the line. Paint is good then just save it. Click the cube, go to mesh renderer(still in the cube), go to materials (Inside mesh renderer), then on the element, pick the picture of your desired picture. Your picture must be inside the Assests folder. Make your picture into a material first then add it in the element in the mesh renderer.