The present invention adopts coli-enhancer to detect carrier. A 894 bp fragment (called M fragment) with enhancer-like function is cloned from coli-chromosome DNA, and at the same time it proves that about 300bp fragment (called X fragment) of PL initiator upstream regulating and control zone and SV40Hind III B fragment, vaccinia virus Hind III K fragment, RSV G zone, and URR zone of HPV6B and HPV16, etc. have obvious enhancer effect. The above-mentioned both fragments (X fragment and M fragment) can be used to form two types of expression carriers, and those two types of expression carriers have obvious enhancer-like effect for expression of several exogenous genes, and can raise the yield of coli-system recombinative polypeptide medicine by 3-9 times. |