The author attempts to prove a general formulation for gravity whose limited form in solar system gives Newton's general law of gravity. The concepts of mass, motion and time are redefined. The first and second laws of Newton are reformed and the third one is held, while the general law of gravity is removed. Some experimentally verified results of theory of relativity are obtained from new theory. Those fundamental unknowns in connection with dark energy and dark matter are explained based on new theory postulations.