The importance of information about laser radar cross section (LRCS) is introduced. According to basic conceptions, LRCS expressions and the physical meanings are analyzed. Measurement mathematic models of LRCS are deduced according to the principles of radiation transmission and electro-optical detection. The concept of target coefficient such as δ is imported according to the relationships between targets and the sizes of irradiation faculae section. From some aspects such as target coefficient, criterion choices of radiation calibration, performances of laser irradiation system and laser detection system as well as atmospheric environment parameters, sources of measurement error and methods for error reducing and correcting are analyzed. And error source and influence are expressed intuitively by error tree. According to the principles of creditability, interchangeability and usability of measurement data, register requirements of measurement data are proposed and register tables of measurement data are programmed. It is an important reference to characteristics research on laser radar target scattering.