Abstract: The contents of main sugar、organic acid and vitamin C were analyzed during the fruit development of three pineapple cultivars ,including ‘Yellow Mauritius’, ‘Cayenne’ and ‘Tainung 11’. The results showed that the dominant sugars in pineapple fruit were sucrose、glucose and fructose, The content of different sugars was low at the earlier development stage, but increased rapidly with slowing down of fruit growth, and peaked at the ripe stage. Moreover, different cultivars showed remarkable difference in the sugar compositions: the ratio in Yellow Mauritius was 3.71:1.11:1 and the ratio in Cayenne was 2.67:0.74:1. The main organic acids were citric acid, malic acid, tartaric acid, acetic acid, oxalic acid and maleate in pineapple fruit. The concent and ratio of organic acids differened in different pineapple cultivars with the fruit development In ripe fruit, the order of organic acid content from high to low in Yellow Mauritius was citric acid(65.7%), malic acid(24.9%), acetic acid, oxalic acid and maleate in Bali fruit’ while In ‘Cayenne’, it was citric acid (62.2%), malic acid(14.4%), acetic acid, oxalic acid and maleate. There were abundant vitamin C in pineapple fruit and the larger differences in the content of vitamin C of different cultivars, it was the lowest in ‘Tainnung 11’ (0.11mg/g) and hightest in ‘Yellow Mauritius ‘(0.49mg/g).