Abstract: This paper studied the effect of hydrothermal treatment time of support on physical structure and HDCCR activity of catalysts. The catalysts were characterized by BET, TPR, Raman spectrum, TG, HRTEM. It is shown that with the increasing of hydrothermal treatment time of the support, the number of -OH groups on the support surface increases. The catalysts made from hydrothermal treated supports have higher specific surface area and lower mean pore size. Those changes indicate that the interaction between metal and support increases with increasing of hydrothermal treatment time, resulting in changes in the structure of active phase of catalysts. The active phase size becomes smaller and the degree of aggregation decreases. The performances of catalysts were evaluated in an autoclave and the results show that the HDCCR and HDS activity of the catalyst are both decreased as the hydrothermal treatment time is prolonged.