Leaf dying score (LDS) Guinea grass and Napier grass have not significant effect of drought stress treatment. Treatment DS2, DS25 and DS258 have not significant difference with control on Guinea and Napier grasses. Relative water loss ratio affect by treatment of drought stress. Relative water loss ratio showed significant difference with control on Guinea and Napier grasses. Stress period DS2 to DS258 significant increased RWLR on Guinea and Napier grasses