The present study was carried out during four growing winter seasons (2012/2013 to 2015/2016) at Shandweel Agricultural Research Station, Research Center Ministry of Agriculture Egypt. The basic material used in this study consisted of (Master-B x Mammoth melting sugar) F₁ hybrid which  all plants have purple flowers and both round and mottled in seed shape and color, respectively and planted  to produce F₂ population which isolated two population categories (purple flowers, mottled seeds and white flowers, green seeds). Data of both F₃ and F₄ generations were studied in four groups, i.e. Wrinkled green seed, Round green seed, Round mottled seed and Wrinkled mottled seed.  Analysis of variance showed significant differences among the genotypes for all characters. Mean values for F₁ generation were high in shilling %, no. of pods/plant and green pod yield. Estimates of the genetic parameters from the generation means indicated significant both additive [d] and dominance [h] gene effects in some traits of the base population, i.e. plant height, No. of pods/ plant, Shelling %, 100-fresh seed weight and Fresh pod yield/plant. Inbreeding depression in green seeds segregations was uniformly less in magnitude than that obtained in the mottled seeds segregations. Most F₂ progenies showed strong evidence of transgressive segregation above the parental values of both green and mottled seed segregations in most traits. Small differences were observed between PCV and GCV for all the characters. High heritability associated with high genetic advance was observed for most studied characters. The potence ratio displayed over dominance in the inheritance of Pod length, Pod weight, No. of pods/ plant, Shelling% and fresh pod yield plant. The estimates of  broad sense heritability after the end cycle of selection were medium for number of  seeds/pod in the wrinkled (52.33%), round  (50.65%) of green seed and only round  of mottled seed (56.74%), while it was of high  magnitude for each of all other traits in all categories. From the results, therefore, it is demonstrated that a considerable amount of readily fixable variation is present and available for the plant breeder to manipulate. It could be noticed that selection for plant height trait in mottled seed (Round and wrinkled) category and for pod green yield trait in only round seed category generally, was better than any other categories over all comparisons after the 2^nd cycle.  Means of 100-seeds weight,  No. of pods/ plant and fresh pods yield were higher in round seed compared with wrinkled one of both green and mottled seed while No. of seeds/pod exhibited the reverse trend in both F₃ and F₄ generations.