Abstract: AIM: To explore the fibrinogen evaluation problems and solution in phase I clinical trials.METHODS: Through a new phase I trial,there were 54 cases in phase I clinical trial volunteers' fibrinogen test, and analysised the results.RESULTS: Fibrinogen change did not exist consistency ,between 30 cases in single dose trial,there were 26 cases fibrinogen reduced ; In subsequent continuous drug trials to join the comfort drug group, the results of the two groups still did not exist consistency between groups, trial drug and placebo group fibrinogen appear consistency changes ,confirm the changes of fibrinogen is none of test drug.CONCLUSION: Fibrinogen test is affected by many kinds of factors, should be standardized operation process to reduce the influence; identify proper testing index range and inclusion criteria; can install placebo group if necessary, using a variety of means for causality assessment of the laboratory adverse events.

Key words: Phase I clinical trial, Fibrinogen, Relevance judgment