This study included 4 cantaloupe varieties (2 Unnetted i.e. Honey Dew and Charentais and 2 netted i.e. Primal and Total) and 3 ethrel concentrations (0.0, 500, and 1000ppm). Fruits were dipped in ethrel solution after harvest then stored under cold storage. Results were recorded changes in physical and chemical composition in fruits during storage i.e. weight loss, decay, firmness, T.S.S., total sugars, and Vit.C. Regarding the weight loss and decay percent exhibited significant and increase at cold storage for 28 days, while there were significant and gradual decrease in firmness values. However, Honey Dew cv. exhibited the least in weight loss percent compared with the other cultivars, while Charentais cv. showed the least in decay percent. Moreover, Honey Dew and Charentais cvs. Showed the highest values of firmness compared with Primal and Total cvs. On the other hand, treated fruits with 500 . 1000ppm with ethrel exhibited higher values in weight loss and decay percent and lower firmness values compared with those untreated. Concerning chemical composition, all these constituents (TSS, Total sugar, and Vit.C.) decreased with the prolongation of storage period. Primal cv. exhibited the highest values of TSS, total sugars, and ascorbic acid compared to the other varieties under test. Moreover, postharvest dipping in ethrel at 1000ppm enhanced fruit ripening senescence in Primal and Total cvs. by reducing TSS, total sugars and Vit.C. Whereas such treatments with Honey Dew and Charentais cvs. enhanced fruit ripening and reaching to the edibility.