In close binary system Her X-I/HZ Her,the gradual occultations of the X-ray pulsar Her X-1 by its companion HZ Her offer a direct observational evidence of the atmospheric structure of HZ Her.The transitions in two observations have been fitted and studied.We find that there exists a chromosphere layer with temperature about 8×10
4K due to X-ray heating at the bottom of HZ Her atmosphere facing the X-ray source.This conclusion is compared with previous theoretical models of HZ Her atmospheric structure.It agrees roughly with the models.Some disagreements are discussed briefly.