Which is the strongest muscle of human body?

well, of your appendages, your leg muscle is pretty strong; stronger than your arms or back or anything.

Your tongue is extremely strong. i don't know the numbers, but if it was the size of your arm, you would be able to lift a car with ease (not over your head of course)

And your heart keeps beating for as long as you live, so i'd assume its very strong too. most likely your heart or tongue. maybe your throat or intestinal muscles.

my moneys on the tongue.

The strongest muscle in the human body is the masseter (in your jaw) the tongue is actually made up of multiple muscles therefore it cannot be the strongest single muscle in the body. As for the answer above, there are many muscles in the human leg not just a "leg muscle".