Abstract: In order to study the microclimate characteristics of plastic greenhouse tea garden and its effect on yield and quality of tea green, experiments were carried out with three modes of tea garden which were normal tea garden, plastic greenhouse tea garden with insect prevention net and plastic greenhouse tea garden with insect prevention net and shade cloths, to determine the ecological environment factors of tea gardens (including the illumination, relative humidity, temperature and soil moisture content), yield and biochemical indicators of tea green (including amino acid, theine, tea polyphenol, chlorophyll) in constant two years in Qiaoli Tea Garden, Gaochun, Nanjing. The results showed that the temperature were comparatively stabile in plastic greenhouse tea gardens, but the illumination was lower and the yield of tea green increased. The amino acids and chlorophyll contents of tea green in spring, summer and autumn were increased, but the theine and tea polyphenol contents were decreased in spring tea green and increased in summer and autumn tea green. The plastic greenhouse with shade cloths can improve tea quality, especially, the yield and quality of summer and autumn tea, but was unfavorable to the tea green yield of spring and before Tomb-sweeping Day. So the plastic greenhouse should be covered without shade cloths in spring and with it in summer and autumn.

Key words: plastic greenhouse tea garden, microclimate characteristics, tea green yield and quality, Nanjing region