Abstract: In order to assess the effects of corncob treated with molasses and urea on production performance and blood biochemical indices of beef cattle, a total of 24 healthy beef cattle were chosen and randomly divided into two groups, including one control group fed with dry corncob and one treatment group fed with corncob treated with molasses and urea. The experiment lasted for 70 days, including 10 days of pre-experiment, and the 60 days of formal experiment. At the end of the experiment, the indexes associated with growth performance and blood biochemistry of the beef cattle were determined and statistically analyzed. The results showed that the crude protein content of corncob treated with molasses and urea was significantly higher than that of untreated dry corncob, and the content of neutral detergent fiber and acid detergent fiber is lower than that of untreated dry corncob; the average daily gain of treatment group reached up to 1.55 kg, which which was 30.25% higher than that of the control group, and was significantly higher than that of control group（P〈0.05）; The content of serum urea nitrogen in experimental group was significantly higher than that in control group （P〈0.05）, but there were no significant differences in total serum protein, albumin, globulin, creatinine and alanine aminotransferase（P〉0.05）;the profit of each beef cattle in the experimental group was 399.58 yuan more than the control group. Taken together, we concluded that the nutritional value of corn cob could be improved by compound treatment of molasses and urea; beef cattle fed with corncob treated with molasses and urea can improve the production performance and fattening efficiency of beef cattle, and had no adverse effects on beef cattle health.