SPECTRAL STUDY OF BE/X-RAY BINARY LSI+61°303

New optical intermediate dispersion spectra of the periodic radio star LSI+61°303 are presented. The Her emission line shows a typical shell absorptionspectrum, which means that the primary of this Be/Xray binary may be a nearlyequator-on Be star. The Her emission line profile and its variation are analyzed,and some parameters such as the Ha Ed and V/Rpeak ratio change strongly nearthe radio maximum, and may exhibit periodic variability. Instead of having a widerminimum lasting for about half an orbital cycle as radio flux and Vmagnitude do,the Her EWshows a deep minimum at phase ～0.75. The accretion disk around theneutron star formed near its periastron passage is suggested to be responsible forthe change when it eclipses the primary and its envelope.