Tooth replacement pattern was observed in Villus Noctule Bat (Nyctalus velutinus) in 1997 and 200 specimens had been involved in this study. The dental formula of milk teeth was I 2/3,C1/1,PM2/2,M0/0=22.The first decay and eruption of tooth took place in 4 days and 14 days after birth,respectively. The termination of decay and eruption was in 31 days after birth. The sequence of decay of the milk teeth were PM²,PM¹,C¹,I¹,I² in upper jaw and I₁,PM₂ or I₂,I₃ ,PM₁,C₁ in lower jaw. The eruptional sequence of the permanent teeth were M¹,PM²,or C¹,M²,PM¹ or M³,I¹,I² in upper jaw and M₁,I₁ or PM₂ ,I₂ or M₂,I₃ or PM₁,C₁,M₃ in lower jaw.