An optical filter system for florescence observation comprises an illumination light filter (I) and an observation light filter (O). The observation light filter has plural transmitting regions (D1O,D2O) allowing fluorescent light to traverse the observation light filter. Blocking regions (S0O,S1O) separate the transmitting regions. The illumination light filter has transmitting regions (D0I,D1I) where the observation light filter has a corresponding blocking region. The illumination light filter has blocking regions (S1I,S2I) where the observation light filter has a corresponding transmitting region. The plural transmitting regions of the illumination light filter hallow for an improved color impression in the normal light observation.