Abstract: Bi-functional catalysts Pt/Al-MCM-41 with different Si/Al ratios were prepared and characterized. These catalysts were used to prepare bio-jet fuel via hydrocracking of bio-alkanes from biodiesel hydrodeoxygenation. The effects of temperature (300~340℃), weight space velocity (0.75~1.75 h^-1), pressure (1~5 MPa) and hydrogen/oil volume ratio (700~2700) on bio-alkane conversion and selectivity were examined. The results show that conversion is significant increased and kerosene/gasoline ratio decreases with the increase of reaction temperature, while the opposite is found with the increase of weight space velocity. Product composition shows little change under low pressure (2~4 MPa), but the conversion decreases rapidly at 5 MPa. Both conversion and kerosene/gasoline ratio improve with the increase of hydrogen/oil volume ratio. The optimum operating conditions considering catalyst selectivity and conversion are temperature 330℃, weight space velocity 1 h^-1, pressure 2~3 MPa and hydrogen/oil ratio 2200.