Classifying heterotic groups of super-sweet corn inbred lines， selecting inbred lines of high combining ability and constructing new stronger heterotic groups could provide basis for breeding excellent sweet corns. 23 self-bred super-sweet corn inbred lines were used to make up 60（ 3× 20） hybrid combinations with NC Ⅱ design to classify heterotic groups by analyzing the combining ability of yield and 56K SNP markers. The results indicated that the average heterozygosity of 23 inbred lines was 2.59%， and the homozygosity was higher. Except for GX06 and GX10， GX14 and GX15， GX16 and GX17， the genetic similarity between the inbred lines was less than 90%， which could be used as different inbred lines in breeding. The positive effect value of GCA in yield of the tester line GX21 and the tested lines GX01， GX03 GX12， GX13， GX18 was higher and they were excellent inbred lines. The results of evolutionary tree， PCA and clustering diagram of SCA classified the 23 super-sweet corn inbred lines into GX21 group， GX22 group and GX23 group. GX22（ HJZ33） group was named the male parent group， including 5 inbred lines（ GX02， GX11， GX19， GX20 and the tester line GX22）， GX21 （ GTL273） and GX23（ YC26） groups were named the female parent groups， including 18 inbred lines（ GX01， GX03-GX10， GX12-GX18 and the tester lines GX21 and GX23） . The results of SNP markers agreed with SCA of yield basically and using SNP markers to classify heterotic groups could shorten the corn breeding cycle significantly.