The Indo-Pacific convection oscillation (IPCO) is out-of-phase convection anomalies over the north Indian Ocean and western North Pacific. Recent study shows that the IPCO is closely related to the East Asian summer monsoon. However, the formation mechanism of the IPCO has not been discussed, and there are no systemic analyses regarding the effects of the IPCO on the tropical cyclone activity over western North Pacific. By using observation datasets, employing statistical analysis and dynamic diagnosis method, and combing with the theoretical analysis and numerical simulations, this project will explore the air-sea interaction processes associated with the interannual variations of the IPCO, and study the influence and relevant mechanism of the IPCO on the tropical cyclone activity over western North Pacific. The implement of relevant work would improve the understanding of the variations of the IPCO and the East Asian climate, thus it would be helpful in both the scientific endeavor and practical significance.