In the framework of general relativity, systematically solve the problem of galaxy formation and some significant cosmological difficulties. Einstein¿s equation of gravitational field is first modified, space-time is proved to be infinite, expansion and contraction of universe are proved to be in circles, the singular point of big bang didn¿t exist, Besides, it is disclosed that galaxies form from unceasing growth but not the assemblage of existent matter after big bang, new matter continuously creates in the interior of celestial bodies, and celestial bodies, galaxies and space simultaneously enlarge at the same proportion, it is the local effect of space-time expansion that determines formation and evolution of galaxies. Also, in detail explain gravitational anomalies of solar system such as extra receding rate of lunar orbit, the increase of astronomical unit, the secular change of day length, the earth¿s temperature rise gradually, the sun is becoming brighter and brighter, as well as the extra acceleration of artificial aerocrafts and so on, these questions can not be treated by current knowledge.

Jian Liang YANG, another name: Ming YANG, Professor, Researcher of theoretical physics, physical department of Zhengzhou university, Zhengzhou, Republic of China. Another address: Henan Province, Zhoukou HuaiYang Police.