An analytical method for the calculation of airgap magnetic fields in a surface permanent magnet synchronous motor with eccentric magnet pole by dividing the region into parts was presented. The solution area was divided into permanent magnet region, air gap region, and stator slot region. Based on the separation variable method, the correlation coefficient was obtained by using the boundary conditions of each region. The analytic model could calculate the distribution of noload and load magnetic fields with eccentric magnet pole. The calculation results of the analytical model were compared with those of the finite element analysis. The results showed that the analytical model had high accuracy.