This paper reported the effects of copper, zinc and methamidophos on the embryo development and larva survival of loach paramisgurnus dabryanus. The 24h LC50 of the embryos and 24h, 48h, LC50, and safe concentration (Sc) of the larvae have been obtained. The results show that both the embryos and larvae could be influenced in some degrees by three toxicants toxic intensity of copper is higher than zinc, and both of them are much higher than methamidophos. In comparison with embryo, the larva is more sensitive for the those toxicants.