Classical model of a symbiotic star contains a red giant and a hot compact star which ionizes substantial part of the giant's wind. CH Cyg does not fit this simplified picture. Its symbiotic appearance was revealed first in 1963 only, and thereafter there have been several active and inactive periods. The presentation concentrates mostly on the optical spectroscopy and photometry of CH Cyg in 1996-1999, but some data from the earlier epochs will be applied, too. In general, the emission line spectrum of CH Cyg in 1996 and most of 1997 could be characterized as "nebular", containing strong forbidden lines of [NII], [FeII], [OIII] and narrow single-peaked Balmer lines. In late 1997 the H_alpha line became double-peaked, and the forbidden lines began to fade. Such a situation lasted throughout 1998, with the Balmer lines becoming strongest around JD 2451000. Before that a radio outburst was detected. In early 1999 the Balmer lines became weaker again. Correlations between various spectroscopic and photometric characteristics are discussed, and an attempt is made to explain behaviour of CH Cyg in the framework of the magnetic rotator model proposed by Mikolajewski & Mikolajewska in 1988.