Objective To explore the quality of randomization of RCT in medical periodicals of China.Methods We designed a table of quality evaluation of RCT.and then randomly chose 137 articles entitled with "random control",which were published in 1995,2000,and 2005.Results Of the 137 articles,103 meet the requirement of this research.Of the 103 articles,99 didn't include the details of randomization (96.1%),100 didn't present the sampling methods(97.1%).Articles published in 1995 totally didnt include the introduction of randomized sampling And grouping methods, but the situation got beuer in 2000 and 2005.There was 63.1% included clear description of diagnostic criteria.Of remaining of 36.9%, 23.3% included either in drawing or excluding criteria,50.5% included both, and 26.2%included none,For grouping,69.9% included the introduction of the baseline of each group, and 30.1%didn't.Conclusions There were some problems in the RCT,such as lack of rigorous in randomization, incomplete in diagnostic,in drawing,and excluding criteria,and lack of clear introduction of the baseline.which revealed there were still much work needed to be done to improve the clinical research level in our country.