abstract
we investigated the field stars around the open cluster M67 of 2500 stars in the area of old open cluster M67. absolute proper motion of M67 is derived using the the extra-galactic objects such as galaxies and quasars which were found in observed field. the CCD data has maximum epoch difference of 4 years. the average proper motion accuracy upto 19th mag is 10 mas/year. the proper motion are used to determine the membership probability of the stars in the region of the cluster. the number of which membership probability is higher than 0.7 is 538. it is found from the analysis of the number density distribution of cluster members than the angular radius of M67 is -8' and corresponding linear radius is 2.1 pc.