Objective This experiment is aimed to analyze the expression state of the thyrotropin releasing hormone ( TRH ) gene at different periods in the development of Gymnocypris przewalskii (“Przewalskii′s naked carp”) embryos. Methods The total RNA of G. przewalskii was extracted to make digoxin-labelled antisense mRNA of the TRH gene. In situ hybridization technology and stereomicroscopy were used to observe the expression status of the TRH gene in the G. przewalskii embryos. Results Microscopy showed that positive hybridization signals of the TRH gene appeared in the diencephalon in the 6-8-day embryo, and appeared in the diencephalon, midbrain, hindbrain and medulla in the 9-11-day embryo. The expression level in the diencephalon was higher than that in other brain areas. Conclusions In situ hybridization shows that the THR gene is expressed in 6-11-day embryos of G. przewalskii, suggesting that THR may play an important role in the brain development and maturation in G. przewalskii.