Abstract: It is significant to precisely calculate the single-well control area，which is not only related to the programme of irrigation project，arrangement of motor-pumped well，total project investment and the exploitable groundwater resources，but also the main considering problem for the water conservancy workers.While，there are different equations to calculate the single-well control area in the current standard.At the same time，some equations have the same letter symbols with different conceptions，which can always make the users puzzled.The different calculated equations for the single-well control area，notions of composite average irrigation quota and rotation irrigation period were discussed.Conclusively，some suggestions for the equation practical use were presented.