The experiments investigated the properties of wheat and corn biochars pyrolyzed at different temperatures. Results showed that pyrolysis temperatures and original materials significantly influenced the properties of biochars. When pyrolysis temperature rose from 300℃ to 500℃, the yeild of wheat and corn biochars (biochar produced by wheat straw and corn straw) decreased from 44.3% to 38.4% and from 42.8% to 29.7%, respectively; the total carbon content of wheat and corn biochars increased from 617.9 g/kg to 674.0 g/kg and from 574.8 g/kg to 651.1 g/kg respectively. For wheat biochar, pH and total P content increased from 7.59 (300℃) to 10.51 (500℃) and from 0.70 g/kg (300℃) to 1.10g/kg (500℃), respectively; for corn biochar, pH and total P content increased from 9.35(300℃) to 10.12(500℃) and from 2.34g/kg (300℃) to 4.37g/kg (500℃), respectively. It indicated that the properties of biochar are depended on the pyrolysis temperature and original materials.