Background: One of common problems of visitors to medical institution is that it takes too long time for waiting on every step of medical services. In case of the general chemistry test, the samples of a high level of substances can be a reason to delay the report time. The samples have a higher level substances than AMR (analytical measuring range) need an extra time to dilute. It causes increased TAT (turnaround time) and also patients’ waiting time. Such as additional TAT delaying for dilution may lead to lose the reliability of laboratory. As the bi-directional interface between HIS (hospital information system) and Automatic chemical analyzer can receive the test request and result report possible, the automatic dilution algorithm has auto-dilution function. It has been developed based on the hospital information system. Methods: We analyzed 893,323 results for 3 months from November 2015 to January 2016, which were commissioned to the department of laboratory medicine, Asan medical center. There were 317,291 cases of ALT (alanine transaminase), 317,170 cases of AST (aspartate transaminase), 22,090 cases of CK (creatine kinase), 146,203 cases of CRP(C-reactive protein), 48,236 cases of LD (lactate dehydrogenase) and 42,333 cases of lipase. The results were analyzed by Cobas c702 (Roche Diagnostics, Indianapolis) and AU5800 (Beckman Coulter, Brea, CA, USA). Results were analyzed by Microsoft Excel (Microsoft, Redmond, WA, USA) program. If the requested test has a record of previous result from 14 days and that was higher than AMR, the automatic dilution are first carried on and then the test is performed, which is the basic structure of auto-dilution algorithms. If there is no previous test result, the test is performed with the original sample. If the first result is out of AMR, the sample is then diluted and re-examined. And the diluted result is reported after applying a dilution rate.This research progresses with the approval of the Asan Medical Center Institutional Review Board (IRB) committee (Accession number: 2016-0221). Results: The analysis of the application for automatic dilution algorithm showed that the result of 3,816 cases (66.2%) among the total of 5,761 cases of subject samples were out of AMR, which means that the efficiency (percentage of results that exceed the analytical measurement range in the results of the automatic dilution algorithm application) was 66.2% and the reduction rate of repeated test (out of the results of the automatic dilution algorithm application, results exceeding the analytical measurement range) was 3,816 case. In addition, 3,816 samples were automatic dilution algorithm to reduce the time required for testing that inspection process was shortened. All efficiencies were above 50% for all items analyzed. Conclusion: As decreasing for spending test time, reporting time was also shortened as well and it improves the satisfaction form clinical doctor and patient. Therefore, the auto-dilution function of automatic chemistry analyzer is expected to reduce the number of errors by manual dilution process.