The CCMD-3 Task Force has prepared and completed field trials for the Chinese Classification of Mental Disorders Version 3 (CCMD-3). It has also worked on the Treatment and Nursing of Mental Disorders Relevant to CCMD-3, and the Rating Test for Health Problems and Diseases as a set of relevant diagnostic scales and software. From 1996 to 2000, the CCMD-3 Task Force has been actively engaged in prospective follow-up field trials aimed at improving the classification and diagnostic criteria of mental disorders in China. A total of 114 psychiatrists from 41 mental health centers and psychiatric hospitals carried out the trials, considering for the 17 adult mental disorders, and 7 mental disorders with onset usually occurring in childhood and adolescence. Based on the results of the field trials, the Task Force has finalized the CCMD-3. Throughout the phase of initial drafting, each item in CCMD-3 was compared with the corresponding item in the CCMD-2R, and the descriptive definitions were based on the Clinical descriptions and diagnostic guidelines of ICD-10. The diagnostic criteria also refer to the Research Criteria of ICD-10, and the DSM-IV. Following the decision made by the Chinese Psychiatric Association, CCMD-3 has been published as diagnostic guidelines to be used by all psychiatrists across the country.