The traits related to plant height were analyzed with correlation, regression and QTL mapping in two F2 populations derived from crosses of YC2×YF1 and YC1×YF1 respectively. The results indicated that plant height (PH) was significantly and positively correlated with bearing height of primary raceme (PRH), length of main stem internode (MSIL) and main stem diameter (MSD) but not with node number of main stem (MSNN), PRH was significantly and positively correlated with MSNN, MSIL and MSD, MSNN and MSIL was significantly and negatively correlated with each other. In F2 population from a cross of YC2×YF1, five, four, six, three, and two QTLs for PH, PRH, MSNN, MSIL, and MSD were detected by QTLnetwork 2.0, which explained for 45.9%, 45.3%, 66.1%, 55.4%, and 12.6% of the phenotypic variation respectively. In F2 population from a cross of YC1×YF1, three, four, five, one and two QTLs for the five traits mentioned above were detected, which explained for 45.9%, 45.3%, 66.1%, 55.4%, and 12.6% of the phenotypic variation respectively. We concluded that the pleiotropy or linkage between QTLs results in the positive correlation between PH, PRH and MSIL, the additive effect was the main genetic component of PH, PRH, MSIL, and the epistatic effect is the main genetic component of MSNN and MSD. It suggested that PRH and MSIL should be used to select and predict PH indirectly in the early stage, more MSNN and shorter MSIL should be regarded as the target traits for high-yield breeding.