  Taking a hint from Dirac's large number hypothesis, we note the existence of
cosmic combined conservation laws that work to cosmologically long time. We
thus modify or generalize Einstein's theory of general relativity with fixed
gravitation constant $G$ to a theory for varying $G$, which can be applied to
cosmology without inconsistency, where a tensor arising from the variation of G
takes the place of the cosmological constant term. We then develop on this
basis a systematic theory of evolving natural constants $m_{e},m_{p},e,\hslash
,k_{B}$ by finding out their cosmic combined counterparts involving factors of
appropriate powers of $G$ that remain truly constant to cosmologically long
time. As $G$ varies so little in recent centuries, so we take these natural
constants to be constant.
