This experiment was conducted to study a cause of lodging on culm internode. The rice varieties were undergone on injuries by typo on 'Agnes' on Jeonbug Provincial in 1981 year. Long-culmed varieties had extreme lodging injury but short-culmed varieties were not serious. The lodging had weaken tolerance when culm internode was long, weight of internode per unit length was light, and culm diameter and culm wall were thin. The breaking weight of internode was light in lodging rice field. The internode length and the weight of internode per unit length between the breaking weight of internode had significant correlation. Lodging had high tolerance when the total nitrogen was low, phosphate, silica, cellulose and starch contents were high in internode. The difference of culm length and the weight of internode per unit length was high relationship with lodging.