A correlation study is made of the diurnal intensity changes of the O2(0--1) atmospheric band at 8645 ¿ and the [OI> 5577-¿ line, which are observed every 160 s from the ground level by a tilting filter photometer; the photometer, of which the optics consist of three aspheric lenses, is equipped with a cooled photomultiplier RCA-C31034A having a small GaAs photocathode. Simultaneous observations of the O2(0--1) atmospheric band at 8645 ¿ and the [OI> 5577-¿ line has indicated an excellent correlation in their diurnal intensity variations.