Abstract: An overview in fruit cracking of Chumen Pomelo was given, and some factors related to the fruit cracking were analyzed. It was found that the main causes of fruit cracking were the air relative humidity (RH) and the soil water-retaining capacity. The effective measure to avoid fruit cracking is to control RH and the soil moisture content in the pomelo orchard to meet the demands in pomelo fruit development. It is suggested that a microsprinkling irrigation system, set in the available irrigation and drainage ditch and controlled by a monolithic microprocessor, could work in optimal water supply.