Conventional memory tests based on only one run have constant and low faults coverage especially for pattern sensitive faults (PSF). To increase faults coverage the multiple run March test algorithms have been used. As have been shown earlier the key element of multiple run March test algorithms are memory backgrounds. Only in a case of optimal set of backgrounds the high fault coverage can be achieved. In this paper the constructive algorithm for optimal set of memory backgrounds selection is proposed. The backgrounds selection is based on the binary vectors dissimilarity measures. The optimal solutions have been obtained for the cases of two, three and four runs memory testing. Theoretical and experimental analysis has been done which allow to prove the efficiency of proposed technique.