Abstract: Burning in field was adopted in Songnen Plain to study fire speed, fire intensit y, fire scorch, fire shape, shape of burning site and their relationships with c limatic factors, combustible, and combustible bed.Wind speed had the biggest ef fect on head fire speed. In addition to wind speed, relative humidity was the se cond significant influential factor for head fire speed in sunny days, and atmos phere temperature had significant influence after precipitation. The relation of fire speed was head fire speed>flank fire speed>back fire speed.Wind speed w as correlated tofire intensity,fire depth,and shape of burning site significa ntly and positively. A predictive model for head fire speed,fire intensity,and shape of burning site in grassland were established by step statistical method