Abstract: To give the solution for the problem of the hard texture of candied black soybean,a single factor analysis method was applied to compare the soften results of sodium salt varieties for the black soybean to improve the texture quality of the product. Six varieties of sodium salt including sodium bicarbonate,sodium citrate,sodium erythorbate,sodium chloride,sodium hexametaphosphate and sodium tripolyphosphate,were selected as addition agents.The variety,addition step and the level of sodium salts were selected as the influencing factors,and the sensory characteristics and hardness of black soybean were selected as the objective factors to determine the reasonable the sodium salt variety for black soybean processed,and develop the addition step and the addition level.The results showed that sodium bicarbonate had the most significant effect on the softening case of black soybean among the six sodium salt varieties. Sodium bicarbonate might improve the water retention capacity of black soybean,and reduce the hardness and the solid addition rate.These effects were significant in the cooking step and 0.2% sodium bicarbonate added in the cooking step could effectively decrease the hardness of black soybean with premium sensory quality.These results can be used as the references for bean processing.