Abstract: In order to screen the optimal amount of organic selenium in potato spraying,the field experiment method was adopted in this paper to study the changes of physiological and biochemical indexes,quality indexes and yield of potato under different amounts of organic selenium spraying.Results showed that the dosage of the organic selenium 6.0 L·hm^-2,potato leaf soluble sugar content(0.63μg·g^-1),SOD(142.62 U·mg^-1),POD(123.03 U·mg^-1),the CAT were maximum,malondialdehyde（MDA）content in minimum,less than30.95%contrast,extremely significant difference（P＜0.01）,at the same time,the potato piece of starch and protein in tuber was significantly higher than control.The content of potato starch increased first,then decreased and then increased with the increase of the content of organic selenium.Spraying organic selenium could significantly improve the content of starch and protein in potato lumps.The potato yield was the highest in the treatment with 6.0 L·hm^-2,and the theoretical yield was the highest when the concentration of organic selenium nutrient solution was 5.62 L·hm^-2 after the equation was fitted.The selenium content of potato chips increased with the increase of spraying amount,and the selenium enrichment effect was significant.In general,when the amount of organic selenium was 6.0 L·hm^-2,potato yield and quality could be improved effectively.