Gabexate mesylate for injections was determined by ion-pair RP-HPLC at 236 nm on a Zorbax Rx-C18 column with MeCN-pH 3.5 Na camphorsulfonate buffer (55:45) as mobile phase.The calibration curve was linear over the range 12.4-248.0 μg mL-1, the average recovery was 100.0% with RSD of 0.06%, and the precision was 0.27%.