Two pumpkin varieties namely, Balady and White Libi were crossed. Parents, F₁, F₂ and backcrosses were used in this study. Mode of inheritance, nature of gene action, heritability and number of effective genes were estimated. The results showed that fruit weight was quantitatively inherited and over dominance was existed. Broad sense heritability was 32.7%, while narrow sense heritability was 29.4% and from one to three pairs of genes control this character. As for fruit shape index, a dominance to round fruit was existed and one pair of genes control the character. Broad sense heritability was 67.2%, while in narrow sense heritability was 138%. The results of chemical composition indicated that the fruit's rind was higher in protein and lipids than the flesh. The cultivar Libi was higher than the Balady in carbohydrate, protein and lipids. The F₁ showed the highest level of carbohydrates, while the backcross to Libi gave the highest level of  protein and F₂ was higher in lipids.