Abstract：In controlled condition of deep flow hydroponics, the experiment studied the effect of iodine on fruit quality of cherry tomato（Lycopersicon esculentum var. cerasiforme）treated in solutions with iodide（I-）concentrations of 1.0-6.0 mg?L-1. The results showed that there were some influences on the iodine, VC, total acid, soluble sugar and moisture contents of cherry tomato fruit. The iodine content in fruit increased with the increasing of I- concentration，and each treatment was significantly higher than that of the CK. The correlation between iodine in fruits and I- concentration in solutions reached extremely significant level, with the correlation coefficient of 0.947. The VC content in the fruit, of which the plants were treated with I- concentration of 3.0 mg?L-1 was the highest, being 9.7 % higher than the CK or 201.7 mg?kg-1 of fresh weight. There was no significant difference between the total acid in fruit with low I- concentration（1.0-3.0 mg?L-1）treatment and the CK, the minimum of total acid in fruit being 0.64 % with I- concentration of 3.0 mg?L-1; but for plants treated with high I- concentration（4.0-6.0 mg?L-1）, it was significantly higher than the CK. The soluble sugar in fruit significantly reduced, when the plants were treated with I- solution, but there were no significant differences among the soluble sugar in fruit, when the plants were treated with I- concentration from 1.0 mg?L-1 to 5.0 mg?L-1. The fruit sugar acid ratio had no significant difference between the plants treated with I- concentration of 3.0 mg?L-1 and the CK. When the plants were treated with high I- concentration（4.0-6.0 mg?L-1）, the fruit moisture content was significantly lower than the CK and 1.0-3.0 mg?L-1 I- concentrations, but there was no significant difference between the plants treated with low I- concentration（1.0-3.0 mg?L-1）and the CK. To summarize these results, it can be concluded that when the I- concentration of 3.0 mg?L-1 was provided for the growth of cherry tomato, fruits with high vitamin Ccontent, low total acid and moderate iodine content will be obtained, though the influence of the I- concentration on the sugar acid ratio and moisture content were not significant.
