How can i prevent sleep while studying at night?

Studying: Mind sound like common sense, but study earlier. You need your sleep to function next day.

Sleep is important: I understand the need to get a lot of material in and sometimes we sacrifice sleep to do that. But, sleep is an important part of learning and memory consolidation so try to avoid pulling all-nighters if you can. From experience, studying late-night is helped by doing it with others who are studying the same material and doing it actively - question each other, teach each other the material.

We have all tried...: But sometimes your body just needs the sleep! your mind will work better and you will retain more of what you have studied if you are rested. Let yourself get enough sleep and just try to budget your time and activities so you have plenty of time for well-rested study.