The orientation of the major axes of planetary nebulae was investigated and the results are given in Figure 1. The solid line gives the distribution of 132 planetary nebulae as a function of the angle Δϕ between the major axis of the nebula and the galactic equator. It can be seen that the distribution is not uniform, and is not symmetrical about Δϕ = 0. The dashed line gives the distribution of the same nebulae as a function of the angle between major axis of the nebula and the direction of the interstellar magnetic field, which is determined from the stellar polarization measurements of stars close to the individual nebulae. This distribution is less uniform than the first one but is symmetrical about Δϕ = 0. These results lead to the conclusion that the orientation of planetary nebulae is partly determined by the interstellar magnetic field.