A method for determination of ibandronate in ibandronate sodium injection using ion chromatography was established in this study. Ion Pac AS18 was used as anion exchange column. The analysis was conducted with an online eluent generator that automatically generated a gradient of potassium hydroxide (12-70 mmol·L^-1, time program was 25 minutes), and an automatic regeneration suppressor was used to detecte the conductivity. Our results showed that a good linear relationship (R²= 0.9995) was obtained in the measurement of ibandronic acid at a concentration range from 0 to 75.25 μg·mL^-1. As for the determination of the product solution, after being repeated five times, the RSD value of the peak area and retention time was 0.21% and 0.01%, respectively, and the theoretical plate number was more than 50 000, which suggested a good applicability of this method. The RSD value of the ibandronic acid content was 0.80% that was less than 2.0%, which indicated a good repeatability of this method. Recovery rates of the tested samples at three concentrations were between 99%-101%, and RSD of the recovery rate was smaller than 1.00%, which was in line with the requirements of pharmaceutical regulations. This assay method is proved to be satisfactory for determination of ibandronic acid in ibandronate sodium injection with good repeatability, high recovery rate, which can meet the requirements for determination of the main components in ibandronate sodium injection.