Abstract: New-bred super hybrid rice combinations Tianyou 10 hao, Tianyou 122, Wufengyou 128, Teyou 138, and super rice cultivarYuxiangyouzhan were chosen to study the differences of morphological characteristics in South-China double cropping super rice seedling in Guangzhou in the early and late season, 2007. The results showed that,under the ecological conditions of double rice cropping system in the southern China, a significant difference of F-value at 1% or 5% level existed among the tested cultivar and combinations in plant height, leaf number of main stem, stem number each plant and basal width of leaf sheath. Therefore, they are reliable to be ideal morphological characteristics indexes of South China double cropping super rice seedling. And the ideal morphological characteristics of South-China double cropping super-rice at seedling stage were improved.They are 35.0～38.9cm in the early crop and 33.5～37.8 cm in the late crop for the ideal plant height, 5.2～5.8 leaves in the early crop and 4.9～5.2 leaves in the late crop on the main stem,1.5～3.0 tillers in the early crop and 3.0～3.7 tillers in the late crop for the tillers per plant, 0.70-0.75cm in the early crop and 0.51～0.59cm in the late crop for the width of basal leaf sheath.