Improvement of grain protein content is the main objective in soft red wheat breeding programs. The main objective of this study was to investigate the mode of inheritance and combining ability of grain protein content in wheat. Seven genetically diverse soft red wheat cultivars were crossed in an incomplete 7×7 diallel fashion. F1 and F2 progenies along with their parents were evaluated in two separate experiments to do F1 and F2 diallel analysis. The results indicated significant differences among the parents for general combining ability and crosses for specific combining ability. Among the parents Ningmai 9 was the best combiner and could be utilized for developing soft wheat cultivars with low protein content. The specific crosses for grain protein content were Ningmai 8×Ningmai 9 and Ningmai 8×Yangmai 5. The additive-dominance model was adequate for grain protein content in F1, while showed partially adequate in F2. Greater value of additive (D) over dominance (H1 and H2 ) demonstrated additive nature of genes for grain protein content in both generations. Grain protein content exhibited high value of narrow sense heritability. The genetic analysis suggested that grain protein content could be improved through pedigree and progeny selection.