After coated by diluted modified chitosan solutions with different concentrations, the oranges were stored at ambient temperature in cardboard for 7-8 weeks. The effect of various chitosan coating on fruit ripening behavior and physical characteristic such as freshness, loss weight, color of skin, surface strain...were evaluated during storage. The overall results showed the superiority of modified chitosan solution of 300ppm in prolonging the shelf life of orange as compared to control and other Concentrations.