BACKGROUNDS: The soybean is one of the most important diet protein resources and induces a reduction of joint pain. OBJECTIVES: The aim of the present study was to determine the incidence of joint disorders and arthritis, especially in the knee joint. METHODS: According to the feed regimens, 36 female mice (balb/c; 3 weeks old) were divided into 3 groups including Group 1: Low protein for 6 months; Group 2: Low protein for 3 months and then followed by complete (or full) protein without soybean meal for the next 3 months and Group 3: Low protein for the first 3 months and then followed by complete protein with 20% soybean meal for the next 3 months. Finally the serum alkaline phosphatase (ALP) was measured and sections from the tibial cartilage were histomorphometrically studied. RESULTS: The thickness of the middle part of the tibial cartilage and the number of chondrocytes in the group used soybean meal (148.84|?|14.05,12.77|?|1.57, respectively) showed a significant difference compared with the other groups (p<0.001). Meanwhile, serum ALP levels (76.402L/U) and the concentrations of the inter-cellular substance in the 3th group showed no significant difference compared with the other groups. CONCLUSIONS: It is concluded that soybean may effect on the growth of the knee joint cartilage in animals and also may induce stability of the knee joint cartilage in individuals with protein deficiency since childhood.