Objective To study The influence and preventive measures for the test results of total bile acid about blood Lipid testing reagent. Methods In Mindray BS -300 automatic biochemical analyzer, we detected total bile acid of the fresh mixed serum separately, then we tested the same samples after the test items of cholesterol, triglycerides, high -density lipoprotein, low - density lipoprotein. Then using fresh serum mixed with normal saline and blood lipid reagent according to 1: 1 dilution ,we measured TBA. We did cross - contamination corrected test (by the anti - cross - contamination to repeat the first step after the test) and recorded all results and had statistics analysis. Results This experiment found that reagents Ⅰ of TC, TG and the reagent Ⅱ of HDL - C , LDL - C had significant positive interference in determination of TBA results. After being corrected by anti - cross - contamination, the results returned to normal. Conclusion When using the automatic biochemical analyzer, we not only acquired the worker fououed of the equipment, and reagents, determined principle, but also pay attention to cross - contamination among reagents, and then in accordance with the equipment work characteristics to establish the appropriate measures to eliminate them, so made sure the reliability of the experimental data to provide clinic with the true objective and actual diagnosis evidence fundamentally.