Fruit abscission in off-season longan is very serious during fruit development in Hainan, China, and severely affectse the formation of production. However, the research on the regulation of longan fruit abscission mainly is focused on fruit thinning, and there are very few studies on fruit preservation. The mechanism of abscission is mainly focused on hydrolase genes and reactive oxygen species, there is no report of fruit respiration on carbohydrate metabolism affecting fruit abscission. Previous studies showed that the decrease in carbohydrate level in fruit was closely related to fruit abscission. In order to further understand the relationship of carbohydrate metabolism and abscission, fruit clusters of off-season Chuliang longan were detached from tree body, the peduncles were immediately inserted into pure water and defoliation treatmented after detachment, which caused starvation stress and induced fruit abscission. Therefore, detachment of the fruit clusters from the tree served as starvation stress treatment. Change in the fruit abscission rate in the starvation stressed fruit clusters, respiratory oxygen consumption rate and fruit removal force in the three developmental stages under detachment were examined, and the effects of different light intensity on fruit respiration in the three stages were analyzed. It was found that longan fruit at different developmental stages differed in sensitivity to starvation stress, which rapidly initiated the fruit abscission response in all the three stages, but there were large differences in speed of fruit shedding. Young fruits responded to starvation stress for two days later than those in the middle and the late fruit development stage would lead to more intense fruit abscission response in the middle and the late stages. Respiratory oxygen consumption rate was the lowest in the young fruit stage. With the increase of light intensity, the respiration of young fruits did not cause a decrease in oxygen, but rather a release of oxygen. The decrease in the fruit removal force was also slower than that in the middle and late stages of fruit development. Therefore, it is concluded that fruit respiration was closely related to fruit abscission under starvation stress. Stronger fruit respiration intensity would result in faster fruit abscission under starvation stress and faster fruit removal force decreases. Young green fruits may carry out photosynthesis, which partially compensates for the respiratory consumption of carbohydrates in fruit, resulting in slower fruit abscission under starvation treatment. In the longan young fruit stage, the main reasons of slow fruit abscission under starvation stress are low respiratory oxygen consumption rate and certain photosynthetic capacity. Therefore, it is conclude that the young longan fruit is a partially autotrophic organ.