  We have analysed several multiwavelength optical observations (H_alpha,
H_beta, H_epsilon, Ca II H & K, Ca II IRT lines) of chromospherically active
binary system OU Gem, taken in three observation runs: March 1996, April 1998
(using the SOFIN spectrograph and the Nordic Optical Telescope) and January
1999 (using the ESA-MUSICOS spectrograph and the Isaac Newton Telescope). The
spectra show double H_alpha and H_beta absorption lines, but after applying the
spectral subtraction technique, clear excess emission is seen in both
components. The two stars have the Ca II IRT lines in emission, strong emission
in the Ca II H & K lines and small emission in the H_epsilon line. Although
they have very similar spectral types, the cool one is more active than the hot
one in all runs, except for MUSICOS run, and in all spectral lines, except for
Ca II IRT lines.
