To construct the conjugation transferring system between rare actinomycetes Micoromonospora and E. coli which can transfer foreign genes into Micoromonospora, a 4.7 kb fragment containing the replication region of plasmid pJTU112 was cloned into the BamHⅠ site of vector pOJ260 which can be replicated in both E. coli and Micromonospora. The plasmid pSCU207 was introduced into E. coli ET12567 carrying pUZ8002 and subsequently transferred by conjugation into Micoromonospora sp. LXH20 with selection of apramycin-resistant colonies,exconjugants were obtained. The plasmid pSCU207 was introduced by conjugation into Micromonospora sp. LXH20 and stably maintained in Micromonospora sp. LXH20. The optimal conjugation volume of E. coli ET12567 carrying pSCU207 and Micromonospora fresh mycelium was 40 μL and 400 μL,respectively.