Abstract:The changes in contents of lycopene, beta-carotene, sugar and endogenous GA and ABA during the fruit development of‘Cara Cara’orange were studied. The results showed that contents of lycopene and beta-carotene in the flesh of Cara Cara accumulated rap idly during fruit expanding period and reached maximum at fruit coloring period (November, 12) and both falled a little during fruit maturation. The content of sucrose increased rapidly before fruit coloring and accumulated slowly during fruit maturation. The contents of glucose and fructose accumulated slowly before fruit coloring and increased rapidly during fruitmaturation. The content of GA decreased rapidly during fruit expanding period and decreased minimum before fruit coloring (October, 10) , after that maintained a lower level. The content of ABA reached maximum before fruit coloring through two rapidly accumulated courses, and decreased rapidly during fruit coloring and maintained a high level during fruit maturation.