Applying biochar to soils is a method to improve crop yield and soil fertility. The aim of this study was to investigate the effect of biochar on crop yield and some soil properties. Biochar was derived from wheat straw at different temperatures (200-600 ̊C), and according to the amount of the stable organic matter yield index (10.06 %), the temperature of 3 ̊C was chosen as the optimum temperature. Moreover, 12 lysimeters (0.8 m×1.2 m) were set up, and filled with loam-sand soil. Then, biochar treatments were added into lysimeters with different dosages (0, 10, 25, 50 t ha-1 (B0, B1, B2 and B3)) in August, 2017. The crop yield of maize were collected in November, 2017. Soil properties were analyzed after the harvesting. The results indicated that the application of biochar decreased the soil bulk density, and increased the soil organic carbon (SOC), total N, total porosity and the cation exchange capacity (CEC). The diverse dosages of biochar of B1, B2 and B3 could enhance the grain yield by 12.86%, 35.83% and 54.29%; respectively. Furthermore, biochar with dosage of 50 t ha-1 showed the most effect on CEC, pH, EC, N and OC of soil. Overall, the current study’s results confirmed that the added biochar could augment the maize production, and improve the soil characteristics.