Abstract: The dynamics of fresh weight， color parameter， contents of sugar and organic acid were examined in developing field and greenhouse fruits of ‘Zaozhong 6’ loquat （Eriobotrya japonica（Thunb.）Lindl.）. The results showed the temperature in greenhouse was higher than that in open field in early spring. The greenhouse fruits showed earlier developing and coloring than those of open field fruits， the mature period was 40-50 d earlier than that in the open field， and average fruit weight in greenhouse was about 61 g， increased by 69% than that in open field. Change trends of glucose， fructose， sucrose and sorbitol content of loquat fruit in open field and greenhouse were similar. The glucose， fructose， sucrose content increased with the fruit development， while sorbitol showed a downward trend. The sugar content in greenhouse mature loquat were much higher than that in the open field， the total sugar content was 40% higher than that in open field. In greenhouse， the content of quinic acid in fruit sharply declined to a low content with loquat fruit development initiation， then slowly decreased to the mature stage; while the field fruit was firstly increased to a peak and then decreased slowly with the fruit growth. The change trend of malic acid was different from quinic acid， malic acid in greenhouse loquat had a 5 times rise at first and then decreased with the development of fruit. While malic acid in open field fruit had a slow rise trend at the early stages， and then decreased gradually with the development of fruit. The total organic acid content in mature greenhouse loquat was about 034%， which was only half of that in open field fruit. The above results indicated the greenhouse cultivation increased the temperature of early spring， which was favorable to fruit development and sugar accumulation.

Key words: Zaozhong 6 loquat, greenhouse, fruit development, quality