Abstract: By means of the prepared core samples with different wettability, the effect of injected water on the water injection recovery factor has been studied systematically, and the influential laws of wettability on the water injection recovery factor of Kendong Block 29 reservoir has been obtained, that is, with the gradual increase of water wettability of the core sample, the water injection recovery factor firstly increases gradually, and then decreases slowly. The rock wettability index that can make the Kendong Block 29 reservoir posses the highest water injection recovery factor has also been obtained. This has an important instructive significance for developing the Kendong Block 29 heavy oil reservoir.