Research on the Rule of Law in Secret Investigation Measures;

Construction of Rule of Law of Secret Investigation System;

The multidimensional study on the character of secret criminal investigation;

But the circle of procedure law has different understandings of its,therefore,it is necessary to redefine secret criminal investigation and entrust new implication to secret criminal investigation in the angle of the unity of content and form.

As an essential part of criminal investigation, the secret criminal investigation plays a greatly important role during the handlings of criminal cases.

On the ancient investigations of the crimes——A case study in The Intelligent Investigations(Zheyuguijian);