Objective: To constuct and identify a specific siRNA targeting mucins (MUC1) expression vector.
 Methods: A pair of oligonucleotide completing and coding hairpin MUC1-siRNA synthesized were inserted into pGC silencerTM U6/Neo/RNAi vector. Double enzyme digestion, PCR test and DNA sequencing were used to identify the recombinant plasmid. Then, special MUC1-siRNA was transfected into cholangiocarcinoma cells with Lipofectamine TM 2000. In vitro, MUC1 mRNA and protein expression was tested by RT-PCR and Western Blot respectively.
 Results: Double enzyme digestion, PCR test and DNA sequencing confirmed that the MUC1 specific siRNA expression vector was constructed successfully. After transfection, the expression of MUC1 mRNA and protein  in QBC939 (experimental group) decreased significantly (P＜0.05).
 Conclusions: The results indicate that the MUC1-siRNA expression vector was successfully constructed, and the siRNA can significantly inhibit the expression level of MUC1. This study can provide an experimental basis for further research of MUC1-siRNA vector.