Chitosan is an important bio-stimulator for many crops due to its ability to promote the plant defense mechanism. A study to assess the effect of chitosan as foliar spray in enhancing the mulberry leaf quality on three mulberry different varieties (V1, MR2 and G4) was taken up. In this study, five different concentrations of chitosan viz., 25, 50, 75, 100 and 125 ppm were applied thrice at 15 days interval starting from 25 days after pruning (DAP) in early hours of the day. The result showed that foliar application of chitosan had statistically significant effect in almost all the traits studied. Mulberry plants treated with chitosan 75 ppm of V1 had maximum photosynthetic pigments viz., Chlorophyll-a (3.12 mg g^-1), chlorophyll-b (0.85 mg g^-1), total chlorophyll (3.23 mg g^-1) and carotenoids (1.02 mg g^-1); higher moisture content (75.82 %) and moisture retention capacity (72.65) compared to all other treatments. Correspondingly, Chitosan 75 ppm of V1 had more accumulation of primary metabolites as soluble protein (31.21 mg g^-1) and total carbohydrate (20.61 mg g^-1); high amount of macronutrients as nitrogen (4.73 %), phosphorus (0.51 %) and potassium (3.51 %) over the control. The same trend was observed in all three varieties in increasing the mulberry leaf quality. Therefore, the application of chitosan at chitosan 75 ppm on foliage of the plant could be an ideal way to increase the mulberry leaf quality.