Abstract: OBJECTIVE Through the detection of drug resistant genotype in Escherichia coli (E.coli) producing extended-spectrum β-lactamases (ESBLs) from the patients body fluids in Zhejiang Provincial People's Hospital of the department of gastrointestinal surgery, to explore the indoor epidemic characteristics of drug-resistant genes. METHODS A total of 300 samples of different hospitalized patients' body fluids from Aug.2015 to Dec. 2015 were collected, and high resistant E.coli strains with ESBLs were screened by VITEK 2 Compact automated bacterial identification and antibiotic susceptibility analysis system. Drug resistant genes were detected and extended by PCR technique. The resistant gene isoforms were sequenced and confirmed by BLAST analysis. RESULTS Totally 120 strains of drug-resistant E.coli with ESBLs were screened, the mainly resistant gene was CTX-M in 14 strains of drug-resistant E.coli with ESBLs by PCR, and the mainly resistant gene isoforms were CTX-M-14 (64.3%), CTX-M-5 (28.6%) and CTX-M-123 (7.1%). CONCLUSION The primary resistant gene was CTX-M and the resistant gene isoforms were CTX-M-14, CTX-M-15 and CTX-M-123 in E.coli with ESBLs from the samples of the hospitalized patients' body fluids in the department of gastrointestinal surgery.