Abstract: Through normative interpretation of the law,we can see the clue of "witness' testimony in court as the principle and absence as the exception" in the Constitution and Criminal procedure Law of China.Due to the lack of legislation on the certainty of the right of cross-examination,there is no "closed loop" in the legal relationship between the witness,the defendant and the court,leaving no institutional space for the linkage of legal relations.There is a "symbiotic relationship" between the obligation of criminal witness to testify incourt and the defendant's right of cross-examination,and the meta-form of the legal relationship between them in Hohfeld's right theory is "right" and "obligation".The obligation of criminal witness to testify in court must take the right of cross-examination as a reference,and it is meaningful to discuss the two in the context of "right" and "obligation" under the primary norm of criminal procedure and "power" and "responsibility" under the secondary norm of criminal procedure.We should construct the criminal witness testimony system in the context of the return of the right of cross-examination from the four aspects of legislative density,supporting measures,system reform and public consciousness,so as to realize the materialization of the trial and the transformation of the fact-finding mode.

Key words: witness appearing in court, right of cross-examination, legal relationship, Hohfeld, right theory, criminal witness