Abstract: Forensic appraisal plays an important role in criminal proceedings. The amendments of criminal procedural law in 1996 have absorbed some reasonable factors of adversary system, but the evidence rules for forensic appraisal were still unchanged. Since the Decision of The Committee of People's Congress and the General Principal were published, the realization in both legislation and judicial practice has witnessed its development, and urged us to focus on the problems of forensic appraisal. Based on the current four forensic problems in criminal proceedings, traditional concepts of forensic science were analyzed, so as to promote the scientific development of forensic appraisal.