The present investigation entitled “Biochemical changes of mango varieties associated with post harvest salicylic acid treatment and cardboard carton storage” had sixteen treatment combination replicated three times in Completely Randomized Design. At maturity condition mango fruits were harvested and stored in cardboard carton by post harvest application of salicylic acid at 0.1, 0.5 and 1.0 g/l doses. On the basis of two years data analysis it was revealed that maximum pectin content (1.96 and 1.95 %) was recorded in Langra variety at 15 days storage period by 0.5 g/l salicylic acid application. Maximum polyphenol oxidase enzyme activity (56.38 and 56.40 units/g) was reported in variety Dashahari at 5 days ambient storage period by 0.1 g/l salicylic acid treatment. Maximum peroxidase enzyme activity and beta carotene content (463.69 and 464.70 units/g, 3495.93 and 3496.73 μg/100g) was found in variety Dashahari at 20 days ambient storage period by 0.5 g/l salicylic acid application. Highest ascorbic acid content (19.37 and 19.42 mg/100g) was recorded in variety Dashahari at 5 days ambient storage period by 0.5 g/l salicylic acid application. Maximum TSS content (28.00 and 27.00 Brix0) was reported in the variety Chausa at 20 days ambient storage period by 0.5 g/l salicylic acid application. Thus the present investigation indicated that post harvest application of enhanced the quality characteristics of mango fruits during storage in cardboard carton.