Abstract: In recent years, mental disability estimation are more than ever in the practice of forensic psychiatric expertise. The standards about mental disability estimation in the Disability Evaluation Criteria of Traffic Accident Injury are ambiguous and difficult to operate, it cause to different understanding in one case. This article discuss some common questions through 3 aspects in mental disability expertise according to some typical cases, there are the first, we should compare the IQ score before and after injurious in intelligence estimate. The second, the mental disability estimation should be done at least one year after the end of medicine treatment. The third, mental estimate scale should be used in mental disability estimation.

Key words: mental disability, psychiatric expertise, traffic accident