Mesh Render Decal

How to achieve this effect alt text

who can give me a sample!?

Best Wish!

Perhaps you could rephrase the question to make it clear what you mean. The image you posted has no context- what is that supposed to be?

Because of the ambiguity of your question, I can only guess that this is what you mean. In most cases, if you wish to have a decal, you would use a material with one of the transparent or transparent cut-out shaders. They can be found under Transparent category in the shader drop-down.