In order to investigate the relationship among the occurrence of bacterial leaf blight, amount of nitrogen application and planting density, a field experiment was carried out with factorial combinations of N levels (7.5, 15, 30kg/10a) and planting densities (10 imes20,;15 imes30,;20 imes40cm). The results obtained in this study were; (1) The incidence of bacterial leaf blight was increased with increase of nitrogen application; (2) In double amount of nitrogen application (30kg/10a), the incidence of bacterial leaf blight was higher, regardless of planting density; (3) The incidence of bacterial leaf blight in Standard nitrogen application was significantly higher $(R=0.94^{**})$ than at $15 imes30cm$ density and $20 imes40cm$ planting density.