In China , some ophthalmic new drug clinical trials used placebo as control .Two principles should be con-sidered in ethical review when placebo was used in these ophthalmic new drug clinical trials .Firstly, using placebo couldn't lead to irreversible or permanent vision loss .Secondly , there should be proper risk management in protocol and risk dis-closure in consent process .There are several important factors , including effects of standard treatment , risks of using pla-cebo, risk management in protocol and risk information in informed consent form , which should be used to assess the ra-tionality of placebo in ethical review .