Plant height,heading date and number of spikelets per panicle are important agronomic traits of rice.Using BC3F2 population derived from the cross Zhenshan97/ Pokkali,a main effect QTL for plant height designated Qph1,significantly influenced the number of spikelets per panicle as well,was located on chromosome 1 near sd-1.Near isogenic line population,in which Ghd7 and Qph1 were simultaneously segregated,was constructed to analyze their interaction.The results showed Pokkali carried positive alleles at both Ghd7 and Qph1 loci,epistatic interaction between Ghd7 and Qph1 affected plant height.Further analysis found that additive×dominance and additive×additive effect affected plant height.Comparing the phenotypes of nine genotypes in BC3F3 population,the genotype of Zhenshan 97 homozyogous at Qph1 but Pokkli homozyogous at Ghd7 was found to well coordinate the relationship among plant height,heading date and spikelets per panicle,and the yield could reach to a reasonable level.