I am doing computer engineering and i like it. But why i don't studying?

then stop asking, start studying!

Maybe you need a different set of "studying" techniques. Lots of people find it hard to "study" by just staring at a set of equations. Problem-solving is the most effective study method for many students. If there are some things you need to memorize, maybe a study "pal" would be helpful. You could try reciting or explaining various rules to one another. Engineering requires creativity, so you need to "engineer" a more palatable study method!

You don't studying because you like partying better! You will flunk out unless you study. Engineering very hard.