Here we have obtained the BVRI CCD photometry down to a limiting magnitude of
V - 20 for the southern poorly studied open cluster NGC 6631 It is observed from the 1.88 m
Telescope of Kottamia Observatory in Egypt. About 3300 stars have been observed in an area of
100 100 around the cluster center. The main photometric parameters have been estimated and
compared with the results that determined for the cluster using JHKs 2MASS photometric
database. The cluster’s diameter is estimated to be 10 arcmin; the reddening EðB VÞ ¼
0:68 ± 0.10 mag, EðJ HÞ ¼ 0:21 0.10 mag, the true modulus ðm MÞo ¼ 12:16 0.10 mag,
which corresponds to a distance of 2700 125 pc and age of 500 50 Myr