This paper deals with the study of thc early embryonic development of Ranaridibund.It includes the ivision of stages

a normal table of devetopment at28±1℃

description and photographs of the external forms.The whole course ofthe embryogenesis is divided into 25 stages according to the morphological cha-racteristics of the embryos.This is similar to the eases of other anurans.As aspecies

R.ridibund(?) has its own features:1.Among Chinese species

R.ridibund(?) is one of the slowest anurans in therate of embryonic development.It takes 176.4 hrs to complete whole process at28±1℃.2.After muscular response

R.ridibund(?) undergoes a long and obvious hatch-ing stage.3.The elongation of the embryo along the longitudinal axis occurs at neuralplate stage.4.The shedding of external gills can be observed during the formation of theopercula.