S U M M A R YWe determine Euler vectors for 12 plates, including the Philippine Sea plate (PH), relative to the fixed Pacific plate (PA) by inverting the earthquake slip vectors along the boundaries of the Philippine Sea plate, GPS observed velocities, and 1122 data from the NUVEL-1 and the NUVEL-1A global plate motion model, respectively. This analysis thus also yields Euler vectors for the Philippine Sea plate relative to adjacent plates. Our results are consistent with observed data and can satisfy the geological and geophysical constraints along the Caroline (CR)-PH and PA-CR boundaries. The results also give insight into internal deformation of the Philippine Sea plate. The area enclosed by the Ryukyu Trench-Nankai Trough, Izu-Bonin Trench and GPS stations S102, S063 and Okino Torishima moves uniformly as a rigid plate, but the areas near the Philippine Trench, Mariana Trough and Yap-Palau Trench have obvious deformation.