Objective:To investigate the factors affecting the pre-analysis quality in clinical chemistry tests

and to recognize the importance of quality control and management before analysis

also to establish the synthetic management system of pre-analysis quality control.Methods:The database of management system was established by VFP6.0

and the common problems were statistically analysed in clinical chemistry tests from June of 1999 to May of 2002

and the qualified rate of samples was made the quality control index of clinical department.Results:The error occurrence rate of clinical chemistry tests was 1.53‰-2.04‰.The error constitution ratio of pre-analysis

mid-analysis and post-analysis were 64.25%

23.83% and 11.92%

respectively.The first four factors affecting the pre-analysis quality were unstandard sampling

delayed sample delivering

unqualified sample

and unstandard preparation of patients.Conclusion:The pre-analysis quality control of clinical chemistry tests is the essential stage in emphasizing quality control and the prerequisite of ensuring the precise and timely results.It needs the effort and participation of laboratory staffs

clinical medical workers and patients.