A Compression pretreatment experiment was conducted to improve the impregnation of small-sized Chinese fir logs. The results showed that compared with the controls, the impregnation amount, the penetration percentage, the ratio of penetration area and the relative dyeing depth of the pre-compressed products increased by 21.83 kg/m3, 8.21%, 24.49% and 39.23%, respectively. It can be concluded that the compression pretreatment could improve impregnation of the small-sized Chinese fir logs significantly.