In this study, 15 hybrids were developed using half diallel mating design at Kaha vegetable Research Farm, Horticulture Research Institute, Kaliobia Governorate during 2021 to 2023, determination of combining abilities, heterosis percentage relative to both mid and high parent and some genetic parameter for some traits in sweet pepper. In all analyzed traits, there were significant variations in mean performance across all genotypes. Estimates of general combining ability GCA effects showed that the best combiner parents were found to be those of CA 3 (P2) was the most promising for number of days to 50% anthesis flowers (ND), number of fruit/ plant (NF), number of locule (NL), fruit flesh thickness (FFT), total yield (TY) and total soluble solids (TSS). The line CA 4 (P3) was the most promising parent for average fruit weight (FW), fruit diameter (FD), (NL) and (FFT). The line CA 7 (P4) was the most promising parent for (NF), (FL) and fruit shape index (FSI). The parent PA Cal- 2 (P5) was the most promising one for (NL). The last parent PA M -10 (P6) was the most promising for most studied traits i.e. (ND), (FW), (FD), (NL), (FFT), (TY) and (TSS). Estimates of specific combining ability SCA effects showed that the F₁ cross P5×P6 showed the highest positive significant SCA effect for (FW) and (FL) and (TY). The traits of the (ND), (NF), (FD), (FSI), (NL) and (TSS) has a value of Kd/Kr > 1, showing that the genes were more dominant in the parents