The present investigation in Muskmelon (Cucumis melo L.) was undertaken with a view to examine the manifestation of heterosis, to assess the combining ability of the parents and crosses and to evaluate the nature of gene action involved in the expression of yield and other characters in order to suggest a sound breeding methodology for the production of high yielding and better quality fruit genotypes. The experimental material consisted of parents and their F1’s derived by crossing ten different genotypes of muskmelon in a diallel fashion excluding reciprocals. The experiment was laid in different environment partitioned by sowing dates viz., 15th October (E1) and 15th February (E2). Observations were recorded on number of node on which first female flower appears, days to first female flower open, number of primary branches per plant, days to first harvesting, fruit length, fruit girth, fruits per plant, fruit weight, fruit yield per plant, flesh thickness, moisture content, total soluble solids, acidity and total soluble sugar. The results of all the parameters is presented and discussed in this book.