  The standard relativistic de-Broglie--Bohm theory has the problems of
tacyonic solutions and the incorrect non-relativistic limit. In this paper we
obtain a relativistic theory, not decomposing the relativistic wave equations
but looking for a generalization of non-relativistic Bohmian theory in such a
way that the correct non-relativistic limit emerges. In this way we are able to
construct a relativistic de-Broglie--Bohm theory both for a single particle and
for a many-particle system. At the end, the theory is extended to the curved
space-time and the connection with quantum gravity is discussed.
