Abstract: This paper analyzed the misconceptions published in some literatures in recent years that there is no stress sensitivity, porosity is invariable and no threshold pressure in low permeability reservoir during oil field development, and points out the causes of these misconceptions: one is incorrect hypotheses, the other is optional substitution for conceptions. By tracing the sources of a number of basic formulae in rock mechanics, which are the original or fontal researches, some issues about the rock porosity and rock compressibility in field application are discussed. It is suggested that to prevent the mistakes in scientific researches and make some innovations depends only on inheritance and development of previous research results, which is the real starting point of scientific research, while distorting the scientific concepts and blindly denying previous achievements should be inhibited in scientific researches