The nuclear region of the Sc galaxy NGC2903 exhibits a very chaotic structure with eight knots, described by Sandage2 as ``giant H II regions''. Others3,4 called these knots `hot spots'. This nuclear region has a very strong blue and UV emission5-7 and is a 1,420-MHz radio source8. Oka et al.1 made photographic and spectroscopic observations of the central region, giving magnitudes and colour indices for the knots which they designated a-g. Physical conditions and stellar content of the 3-arc s central region were investigated by Alloin10 whereas Turnrose11 analysed the stellar population in the knot c. The nucleus was identified on near IR photographs9. During high resolution-broad band and narrow band-photometric studies of the central region of NGC2903, we have observed and report here that one of the knots (a, according to Oka et al.1) appears 1.3 mag brighter on plates taken in February 1980 than on a plate taken in January 1978, which agrees with other observations taken1 in 1966-68.