Insulinlike growth factors(IGFs)system,including IGFs and IGFbinding proteins,plays a central role in growth and reproduction of fish and higher vertebrates.In serum and extracellular fluids,most circulating IGFs are bound to specific high affinity IGFbinding proteins(IGFBPs)that can protect them from degradation and modulate their actions.Common carp(Cyprinus carpio)is one of the most economically important fish in China.To improve the yield of common carp and get more economic benefits,the study of mechanism of growth and reproduction is very important.In the previous study,the cDNAs of common carp Igfbp-2 and -3 had been cloned,and the expression profiles and hormonal regulation were studied.The results showed that common carp Igfbp-2 and -3 mRNAs were expressed in many various tissues and different embryonic developmental stages,but the abundances were different significantly.To further understand the regulation mechanism of Igfbp-2 and -3,the study of their promoters is necessary.So,in this paper,the sequences of Igfbp-2 and -3 promoters were firstly cloned,and then the putative transcription binding sites were analyzed.The length of Igfbp-2 and -3 promoters we obtained was 1 142 bp and 1 067 bp,respectively.There was a consensus TATA box 22 bp 5′ to the start site of transcription in Igfbp-3 promoter,while in the upstream there was a SP1 binding site instead of CAAT box.Neither TATA box nor CAAT box was found in the promoter of Igfbp-2,only a SP1 binding site and rich G/C motif in this region.These results showed that the promoters of common carp Igfbp-2 and -3 did not contain the characteristics of classic promoter.Furthermore,some other transcription binding sites were observed in the two promoters,such as CREB,HNF,Pit-1,Oct-1,RXR,GR,ER,PR,SRY and so on,while the STAT(signal transducer and activator of transcription)was only found in Igfbp-3.These results suggested that there were basic and hormone inducible expression patterns of Igfbp-2 and -3 genes.However,the regulation mechanisms were not consistent between the two genes.