Abstract:The combining ability and heritability were estimated in progenies of 12 cross combinations of sugarcane （Saccharum officinarum L.） hybridized by using a incomplete diallel cross design for four female and three male parents. Six parameters were used for the analyses of quality characters in sugarcane juice, i.e. brix （percentage of total soluble solids）, polarilneter reading （PR）, pol in juice （Pol）, sucrose content （SC）, apparent purity （AP）, and gravity purity （GP）. The results showed that the heredity of quality characters was induced mainly by additive gene effects. The changes in brix, PR, Pol and SC were affected by male parents. Parents with high sugar-yielding and good combining ability appeared in CP72-330, HoCP93-750, GT91-116 and YT92-1287 which presented high and positive general combining ability （gca）. Whereas for progenies of crosses, CP72-330×GT91-1 10 and HoCP93-750×YT92-1287 showed high and positive special combining ability （sea）. The gca variances in male parcnts were greater than those in female ones. The gca variances in parcnts were grcater and sea variances in crosses by 7 to 28 times. The heritability in broad sense （hB2） in quality characters were from 58% to 68%, and that in narrow sense （hN2） 56%-60%. These results indicated that the data of quality characters had better heritability.