Under field experiment condition,effects of foliar application of Na₂SeO₃ on concentration and form of Se,and protein-bound Se in grains of Longqing 4,86 You 8 and Bing 9 652 varieties of rice were studied in South Jiangsu.Results show that foliar application of Na₂SeO₃ at a rate of Se 10 g hm^-2 could raise significantly Se content in rice up to 255.3～586.5 μg kg^-1,which was 7.9～11.0 times higher than that in CK.Moreover,foliar applicationof Na₂SeO₃ did not show any negative effect on rice yield.Most Se in rice grains was organic Se,occupying over 87.72%～90.98% of total selenium,and protein-bound Se accounted for 43.07%～51.65% of the organic selenium and 38.04%～48.98% of total selenium.Application of Na₂SeO₃ did not affect much distribution of protein.The spectral bands of the grains(Longqing 4 and Bing 9 652)with or with-out Se application were more or less the same,except for some new protein bands between 14～20 kDa,suggesting that Se application might increase formation of some small molecular proteins.