An analytical model was presented for a 5 kW high speed permanent magnet synchronous motor with gramme windings. The solution regions were divided into airgap subdomain, permanent magnet subdomain, slot opening subdomain and slot subdomain. The Laplace and Poisson equations in each subdomain were solved. The analytical model accounted for armature reaction field, permanent magnet field and stator slot effects. Airgap flux density, phase fluxlinkage, phase back electromotive force, cogging torque and electromagnetic torque calculated with the proposed analytical method were respectively compared with finite element calculation results and experimental data. Comparison results illustrated the accuracy of the analytical model. Finally, airgap flux density and cogging torque were studied based on different slot opening grades.