The present study was designed to investigate whether 7 preschool children brushed their teeth by self-evaluation(SE), and to compare the effects of general behavior standard settings with specific ones. The reversal design of single subject designs was used in the present study consisting of 9 phases: 1)pre-check, 2)baseline I, 3)baseline II, 4)SE I, 5)baseline III, 6)SE II, 7)baseline IV, 8)SE III, and 9)revised SE. On SE I・II・III, judgements of SE were based on general behavior standard and revised SE was based on two kinds of specific behavior standards. The results were as follows:(1)children could regulate their toothbrushing behaviors by self-evaluation in a preschool classroon, and(2)it was necessary to set specific behavior standards for SE, then toothbrushing behaviors were remarkably improved.