Hydrogen liquefaction of sawdust in tetralin was performed in an autoclave at below conditions: temperature range from 200 degrees C to 350 degrees C; initial cool hydrogen pressure range from 4 to 10 MPa; reaction time range from 10 to 100 min. The effect of variables on the process of sawdust liquefaction was examined. The results indicate that the oil yield may range from 6.8 to 67.1% at different liquefaction conditions. Temperature has a remarkable effect than initial cool hydrogen pressure and reaction time on the process of sawdust liquefaction. With increasing temperature (200 degrees C - 350 degrees C) the conversion, gas yield, H-2 consumption and oil yield are all increased, but the yield of preasphaltene and asphaltene (PA + C A) increases first (200 degrees C - 300 degrees C) and then decreases (300 degrees C - 350 degrees C). The high heating value of the products is higher than that of the feedstock. With the increase in initial cool H2 pressure (4 - 10 MPa), the conversion and gas yield are almost unchanged, the oil yield increases (36.86 - 57.06%), while the yield of PA C A decreases (28.07 - 16.27%). With increasing reaction time (10 -100 min), both the conversion and the product distribution change little. The existence of H2 or tetralin improves both the conversion of sawdust and the oil yield.