Axolotl's(Ambystoma mexicanum)spawn was incubated at 25℃,and embryos at stages 30-44 were collected and fixed with 4% paraformaldehyde.The whole mount immunostaining was conducted and embryos were observed under stereomicroscope.The sensory ganglion of branchial nerve and smallish branchial nerve trunk were observed in the stage 30 embryo,rami and communicating ramus of branchial nerve appeared in the stage 35 embryo,maxillary and mandibular nerves developed in the stage 37 embryo,dorsal ramus and pharynges ramus of glossopharyngeal nerve were found in the stage 38 embryo,and pretrematicus ramus of glossopharyngeal nerve were observed in the stage 40 embryo.Early stage axolotl embryo kept the same pattern of branchial nerves as in the ancestral vertebrates.In later stage,embryo showed the evolution tendency of the branchial apparatus and branchial nerves appearance and redistribution.The glossopharyngeal nerve of axolotl kept the original morphological characteristic of branchial nerve.