There is correlation between flexural capacity and shearing capacity in RC(reinforced concrete) bending members. Chinese code GBJ10-89, GB50010, JTJ023-85 and JTG D62-2004, as well as American code ACI318 basically follow the same guidelines. They do not consider the bearing capacity correlation between bending and shearing sufficiently. The amount of longitudinal reinforcement and stirrup of a RC bending member is respectively calculated according to its normal section bearing capacity and oblique section bearing capacity. Only for independent beams under concentrated load, the influence of bending moment on shearing bearing capacity are considered through the shear-span ratio. Based on the analysis of the implicit correlation of bending and shearing from GB50010 and ACI318 strength criteria in stress level, and the effect of shear-span ratio in bearing capacity code formula, a modified formula considering the correlation of bending and shearing is put forward. By introducing several typical examples, the amount of reinforcement with different parameters is calculated with the modified formula and the code formula, respectively, and the reliability indexes of the two formulas are compared. Moreover, according to the target reliability index requirements of Chinese code GB50068-2001, the necessity of considering the correlation of bending and shearing in RC bending member is discussed.