Abstract: Analysis of the combining ability and the hereditability was carried on between purple – caitai Male sterile lines（239、240、242、246、249、250、258、259）and Father plants（290-1、288-3）testing 11 main quantitative characters of 16 hybrid combinations on the way of incomplete diallel cross. The analysis of combining ability showed that Father plant 290-1 and Male sterile line 240 which had high GCA could be regarded as good crossing parents. The combinations 290-1×249 and 288-3×259 had high SCA. The analysis of hereditability revealed that the heredity of plant height, leaf length, main stem height and side sprout power was mainly controlled by additive effect; Petiole length and main stem weight were mainly controlled by non-additive effects.