Abstract: In order to breed high-yield hybrid pepper varieties, this study was conducted to analyse the correlation between heterosis of net photosynthetic rate and agronomic character in pepper by the use of 15 combinations hybridized from 6 parents by (1/2)n (n-1) diallel crosses. The results indicated that the heterosis over the mean parental value (mid-parent heterosis) of net photosynthetic rate in pepper was relatively greatly affected by leaf blade and phytophthora resistance at the early phase of flowering and fruiting; then mainly influenced by leaf blade, plant growth vigour and branching ability at the medium phase, which had relatively great effects on fruit growth, yield formation and nutrient content; and then mainly affected by plant growth vigour and branching ability at the late phase, which exerted relatively great effects on yield formation and disease resistance. The heterobeltiosis was more greatly influenced by leaf blade, CMV and phytophthora resistance than by plant growth vigour and branching ability at the early, medium and late phases of flowering and fruiting, which had relatively great effects on fruit growth, yield formation, dry matter and cellulose content.