  We present the relations between Halpha equivalent width, optical brightness
and X-ray flux of Be/X-ray binary system SAX J2103.5+4545, by analyzing the
optical photometric and spectroscopic observations together with the X-ray
observations.
  In the photometric observations PSF photometry were applied using MIDAS and
its DAOPHOT package. The reduction and analysis of spectra were done by using
MIDAS and its suitable packages. The X-ray outburst of the system occurred just
after the optical outburst. The nearly symmetric Halpha emission line profiles
observed during the beginning of optical outburst turn into asymmetric profiles
with increased EW values during the dissipation of Be disc. Halpha lines
changed from emission to absorption during the observation period. The observed
double peaked HeI emission lines might come from the accretion disc of neutron
star which is temporarily formed at the time of X-ray outburst.
