Abstract: Abstract: In order to figure out the optimum stocking density for beef cattle growth and seek the improvement of economic benefits in beef cattle farms, related experiments were carried out at the beef cattle experimental station of Gao'an City, Jiangxi Province from December 26, 2016 to January 22, 2017. In the beef barns with the fixed area of 18 m2, we respectively selected 3, 4, 5, 6, and 9 heads of hybrid cattle with initial body weight between 182 and 282 kg, and thus area per calf was designed as 6.0, 4.5, 3.6, 3.0, and 2.0 m2/head correspondingly. Each treatment with different stocking density was repeated 2 times to obtain exact conclusion. The results of this experiment showed that the feed intake per calve per day which was fed in group of 2.0 m2/head was 11.90 kg, which was significantly higher than that fed in the other treatment groups (P<0.05). Although it held the highest feed intake, frustratingly we found that the weight gain effect was poor, only 1.09 kg per head per day for the 2.0 m2/head group. Calves held in 3.6 m2/head treatment group, which had the middle-level feed intake of 10.96 kg per calve per day, turned out that they gained the best effect of weight gain of 1.41 kg everyday. We figured out the weight gain increased by 29% compared with those treatments that were designed as 2.0 m2/head, respectively. During this experiment, we also surveyed related environmental index to help us evaluate the best stocking density for calves. We found that there were no significant differences in indoor temperature, relative humidity or average velocity between different treatments, but when it came to deleterious gas concentration, especially for carbon dioxide concentration and ammonia concentration, results were different. The conclusions were drawn that with the increase of stocking density, the indoor carbon dioxide concentrations were determined as 1 056.38, 1 108.44, 1 172.65, 1 200.89, and 1 398.19 mg/m3 respectively, showing an upward trend. The calves fed in 2 m2/head treatment group reached a maximum value of ammonia concentration of 3.23 mg/m3, which was 1.44, 1.60, 2.10 and 2.86 times that of the treatments with area per calf of 2.0, 3.0, 4.5 and 6.0 m2/head, respectively, while in 6 m2/head treatment group , ammonia concentration was only determined as 1.13 mg/m3. Different experimental groups held notable differences (P<0.05), and in summary the concentration of harmful gas production was positively related to the number of livestock. For 2 m2/head treatment group, the standing time (including fight time) was determined as 11.84 h per day, and with the decrease of stocking density, standing time reduced. As for the dirt degree, the score was evaluated as 2.09 for the 2 m2/head treatment group, and therefore cattle's bodies in this treatment group seemed to be the dirtiest among all the experimental groups. As for fight time and dirt degree, 3.6 m2/head held the middle state. These findings suggest that the 3.6 m2/head treatment group, which leads to a high feed conversion rate and results in a middle-level animal welfare, is the optimum feeding density for beef cattle with a weight of 182-282 kg and holds great advantage to cattle farm developing.