Abstract: Chemistry effectiveness indicator combines the key hydrochemical parameters of primary and secondary circuits into a single control index,which realizes the intuitive reflection of chemical control effectiveness and the accurate reflection of over-standard items in power plants,and provides suggestions for chemical control improvement. CPI,CEI,IPC,Chinese index have been used gradually. CPI index controls the key chemical parameters such as impurity ion concentration and dissolved oxygen in the secondary circuit from a single dimension. It realizes the intuitive reflection of the effectiveness of chemical control in power plant operation. However,CPI indicators also have some limitations,such as not paying attention to the primary loop control,not paying attention to the cumulative time,hiding the quarter,and benchmarking the ceiling. On the basis of CPI index,CEI index and IPC index were put forward abroad,which extended the control range to key areas such as impurity ion concentration and source term in the primary circuit,and realized chemical control in the whole plant from five dimensions. Paying attention to the accumulation time of impurity exceeding the standard can effectively reflect the long-term accumulation effect of impurity ions. Monthly benchmarking has made up for the "quarterly hidden effect" of CPI indicators. The benchmarking results break through the "benchmarking ceiling" of CPI and impro ves the discrimination of benchmarking results. On the basis of fully drawing on the advantages of CPI,CEI and IPC indicators,and combining with the characteristics of nuclear power units in China,Chinese indicators with Chinese characteristics are put forward. According to the design calculation method,parameter types and limits of domestic M310 and CPR1000 units,chinese index can better reflect the hydrochemical control conditions of domestic units from six dimensions. It focus on chemistry of using tank,and it can provide basis and guidance for chemical control of primary and secondary loop systems of domestic PWR nuclear power plants,and provide technical support for domestic nuclear power units to go global.