In order to study the clinical performance and the evaluation method of light-cured composite resin in filling for posterior teeth, two evaluation methods were used to evaluate 5 light-cured posterior composite resin fillings in 169 adult posterior class I cavity. Results showed that each evaluation method has its own advantages. The curative effect was declined with time in this study. Failures and defects were mainly occurred after 3 years. Secondary caries, loss of fillings and marginal stainings were the main reasons of failures. Compared with the effect of 1 year, the success rate after 3 years declined significantly, and further long-term clinical observation is needed.