Abstract: In order to study the effect of fertilization on the qualities of sweet pepper(Capsicum annul L)cultured in greenhouse,the experiment was carried out by drop irrigation.The results showed that the most sensitive organ of sweet pepper for nitrate was lateral branch,in which the nitrate content was highest.The nitrate content in leaf was lower than that in lateral branch,and in fruit,the nirtate content was the lowest.High fertilization of N,Pand Khad no negative influence on content of nitrate and total soluble sugars in fruit.The content of soluble sugars in fruit were about 50%～55% under all treatment and higher than that in leaf and lateral branch.Decreasing fertilization would cause increasing of the inosital and sucrose contents.Glucose and fructose were the main soluble sugars in fruit.The metabolism of carbohydrates was weakened by high fertilization,and it experessed as restraining the accumulation of starch content in leaf.The content of starch was the highest in fruit.The lipid content were exceed 3～4 times in the leaf than in the lateral branch and fruit,and perhaps,it was due to the hiher content of chlorophyll in the leaf.

Key words: Drop irrigate fertilization, Carbohydrate, Lipid, Quality, Sweet pepper, watershed, ‘source-sink’ theory, landscape pattern, regulation, key ‘source’ landscape, non-point source pollution