Abstract:ABSTRACT: To understand the occurrence of sulphonamide resistance genes and class Ⅰ integrons in Laribacteria hongkongensis(LH) isolates, obtained from freshwater fishes and frogs. The susceptibility of trimethoprim-sulfamethoxazole (SXT) was carried out using the K-B disk diffusion method. Sulphonamide resistant isolates were detected for the presence of sul1、sul2 and class I integrons genes using PCR method. Of the 128 Laribacter hongkongensis isolates, 20 (15.6%) were resistant to SXT. Among 20 isolates of the SXT resistance, 18 (90%), 11 (55%) and 16 (80%) were positive for sul1, sul2 and class I integron genes, respectively. The mechanism of SXT-resistant LH isolates from freshwater fishes and frogs are likely to associate with sul1, sul2 and class I integrons genes.