Three important fields were brought forward such as basic theory,information security and crimes and legal system.

The computerization of social information has provided convenience for human beings, meanwhile, people are deeply puzzled by information crime that network has brought about.

The typological study of information crime as a new type of crime has information society as its background of study and the informational characteristics of this type of crime show the inherent difference between highly technological crime and traditional one.

The informationization of society has become a spur to the enormous development of productive forces in human society, and it has also rapidly improved the criminal abilities of lawbreakers, especially in the field of information crime which has broadened the public security territory from real space to imaginary one and severely challenged the public security.

This investigative method renders us easy to obtain criminal information and it is of high value in investigative tactics and investigative moulds.

Criminal information in spots means various evi de nce of traces that suspects leaved at the crime scene and rational cognition gai ned from the change of the objects in the spots by the investigators.

In view of the future information warfare which our militaries will be confronted with, the necessity of constructing the information security and antagonism network for national defence based on civil information systems was analyzed, in accordance with incorporation military into civilian and use for both military and civilian purpose.