Abstract: [Abstract] Objective：To investigate the bacteriostasis effect of Longliqi DL toothpaste containing dextranase and lysozyme on several species of oral bacteria. Methods：The adhesiveness of S. mutans(Sm) was determined by Dentocult SM test; the bacteriostasis to A. actinomycetemcomitans(Aa), P. gingivalis(Pg) and A. viscosus(Av) were observed by agar dispersion method. Results：The aqueous solutions of dextranase and the toothpaste reduced adhesion of Sm to the Dentocult SM test strip; the aqueous solutions of lysozyme produced clear inhibition zones of Aa, Pg and Av, and the diameter of the inhibition zones increased along with the increasing of concentration of lysozyme; the toothpaste produced clear inhibition zones of Pg and Av and unclear inhibition zone of Aa. Conclusions：Dextranase and the toothpaste reduce the adhesiveness of Sm; lysozyme and the toothpaste has in vitro bacteriostasis effect on several species of oral microorganism.