Two parents of Brassica rapa （P1 ，P2 ） with significant difference in seed pod traits, and their corresponding four basic generations (P1, P2, F1, F2) were used to analyze the inheritance of seed pod correlated traits by applying mixed major-gene plus poly-genes inheritance model. The results indicated that both the seed pod length (SPL) and the seed beak length (SBL) were controlled by poly-genes with additive-dominant-epistatic effects (C-0 model), the heritabilities of poly-genes for SPL and SBL were 83.16% and 68.67%, respectively. The seed pod width (SPW) was controlled by two major genes with additive-dominant-epistatic effects plus poly-genes with additive-dominant-epistatic effects (E-0 model), the heritability of major genes was 20.40% and poly-genes was78.34%. The seed pod width (SPW) was less affected by environmental factors, conversely to the SPL and SBL, which influenced by environmental factors were 16.89% and 25.36%, respectively. This implies that in the genetic improvement of seed pod correlated trait poly-gene is a main factor and environment factor should also be mentioned.