Abstract: A greenhouse experiment was arranged to study the effects of different amount of iodine fertilizer on crop yield qualities and iodine contents on vegetable. On basis of the lettuce normal growth and fertility required, the author used KI at 4 different dosages, the application method were basal dressing and spraying. The results showed that the iodine content in lettuce increased as the KI amounts applying increased, the yields of lettuce increased first and then decreased as the KI amounts applying increased. The highest yield was the lettuce with applying 5 g/m² KI, the maximum yield was 49290.15 kg/hm², the application of KI could increase lettuce yield in different degrees, representing an increase of 10.18% , 1.02% and 3.39% . The Vc content increased in varying degrees, spraying processing was best method to improve the Vc content, the Vc content was 24.7 mg/kg. The lettuce soluble sugar content increased but the crude fiber content and nitrate content decreased in varying degrees, the soluble sugar content increased the most with applying 0.1% KI, while the cellulose content and the nitrate content were the lowest with applying 0.1% KI. In summary, it had significant effect of using iodine on vegetable enrichment. Thus, it had broad application prospects by applying iodine to cultivate rich-iodine vegetables to control iodine deficiency disorders