Nowadays use of the edible coatings has been increased because customers tend to buy horticultural products that retain their freshness. The benefits of edible coatings are biodegradability, inhibition of respiratory gas exchange, inhibition of exchange of aromatic and flavorful compounds, and product protection against mechanical damage. The aim of this investigation was to study the effect of chitosan on preservation of quality and storage life of sweet lime by measuring physic-chemical properties of fruits. The measured parameters in the study were firmness, TSS, titrable acid, pH, vitamin C, weight loss and chlorophyll content. The experiment consisted four treatments of chitosan solution (control, 0.5, 1 and 2%). The results showed that chitosan had significant effects on all measured parameters (p<0.01). Chitosan-treated fruit had firmness, vitamin C and titrable acids more than those of the non-treated control group during cold storage. The highest firmness was observed in 2% chitosan treatment and the lowest firmness was recorded for the control treatment. Fresh sweet lime fruit treated with chitosan 2% had the lowest percentage of weight loss (5.95 %) and the highest TSS (10.6 g/100 ml), titrable acids (0.077 g /100 ml) and vitamin C (44/59 mg/100ml). According to the results of this study, it could be suggested that 2% chitosan increases the shelf life of this fruit.