The inheritance of resistance to phythophtora blight of N1345 is important for pepper breeding resistant to phythophtora blight.Using the model of the major gene plus polygene of quantitative traits, a joint analysis of six-generations from a sweet pepper line N1345 highly resistant to phythophtora blight and a highly susceptible hot pepper line N1308 was performed. It showed that the resistance to phythophtora of N1345 was controlled by two major genes (B-1-1) with equal additive and dominant effects.And the major genes heritabilities of B1,B2,F2 were 63.43%,82.32%, and 83.46%, respectively.