This experiment was carried out to investigate the growth response of 3 grasses to seed coating with chitosan solution and the attempt was made to estimate adequate seed coating concentrations of chitosan solution in each grass for the growth to be stimulated. Three species used in this experiment were orchardgrass, tall fescue and reed canarygrass. Six different seed coating concentrations of chitosan solution were applied as 0%(control), 0.01%, 0.05%, 0.1% and 1.0%, respectively. the results were obtained as follows; 1. Dry weight of tiller(WT), leaf area(LA), dry weight of leaf(LW), dry weight of stem(SW), dry weight of shoot(SHW), biological yield(BY) and C/F ratio were significantly different between species. 2. Number of tillers per plant(NT), dry weight of tiller(WT), dry weight of leaf(LW), dry weight of root(RW), dry weight of shoot(SHW), biological yield(BY) and T/R ration were significantly different between seed coating concentrations of chitosan solution. 3. The adequate seed coating concentrations of chitosan solution for the growth stimulating effect were different between species. The highest values of yield components and dry weight of plant parts were obtained at 1% in orchardgrass and tall fescue, and 0.05% in reed canarygrass, respectively. 4. Growth stimulating effect of seed coating in each species were different. The highest values were obtained in leaf area(LA), dry weight of leaf(LW), dry weight of root(RW), dry weight of shoot(SHW) and dry weight of biological yield(BY) in orchardgrass. The values of dry weight of stem(SW) and C/F ration were highest in reed canarygrass. 5. An increase in number of tillers per plant(NT), dry weight of leaf(LW), dry weight of stem(SW) and dry weight of root(RW) according to seed coating was attributed to the increase in dry weight of shoot(SHW). Among the aboved increasing factors, the dry weight of leaf(LW) was a main factor for the increase in dry weight of shoot(SHW). 6. An increase in dry weight of leaf(LW), dry weight of stem(SW) and dry weight of root(RW) according to seed coating was attributed to the increase in biological yield(BY). Both the dry weight of leaf(LW) and dry weight of root(RW) were main factors for the increase in biological yield(BY).