When i lay down to sleep after some times i feel in night on woking up that iam vibrating why is that?

Hypnopompic state: As people wake up they can often have unusual experiences as the get used to being awake again. This have been called hypnopompic phenomenon. it is probably just your mind reconnecting with your body as you wake up.

Vibrating sensation: Vibrations are very nonspecific symptoms and on their own are not enough to diagnose a disease simply because there are so many conditions that may cause them. Most commonly these vibrations can be divided into two major groups based on their origin. They originate either from heart arrhythmias, from muscle twitching or could be from psychological origin. See your doctor for further evaluation

Possibilities: Most of the time, part of your body is vibrating--your throat and vocal cords with snoring or coarse breathing. On rare occasions, it can be due to seizures, muscle twitching, or low blood sugar