Corticotropin-releasing hormone (CRH), Urotensin Ⅰ (UⅠ) and Urotensin Ⅱ (UⅡ) have been found throughout vertebrate species from fish to human. In fish, these peptides appear to be involved in osmoregulation, reproduction, nutritional behavior and stress responses. Embryos and larvae were collected at 0,1.5,3.7,5.3,8,10,16,24,48,72,96,120 and 144 hpf(hours post-fertilization). Three biological replicate pools (n=50 larvae per pool) were analyzed for each developmental time point. Real-time quantitative PCR results showed that the mRNA coding CRH, UⅠ, UⅡα and UⅡβ was present from 0 hpf, suggesting a maternal function. The relative amounts of CRH, UⅠ, UⅡα and UⅡβ mRNA during the early development of zebrafish gradually increased and reached the highest level at 144 hpf except UⅡα at 120 hpf. Highly significant and positive correlations between each pair of CRH, UⅠ, UⅡα and UⅡβ mRNA expression levels were found. It suggested that these genes were closely linked and cooperated to support a developmental function.