OBJECTIVE：To explore the stability of levofloxacin hydrochloride and carbazochrome sodium sulfonate in 0.9％ Sodium chloride injection， and provide reference for their compatible use in clinic. METHODS：HPLC was performed on the column of Phenomenex Gemini C18 with mobile phase A of acetonitrile and B of 0.01 mol/L Ammonium biphosphate solution （adjusted to pH 3.0 with phosphoric acid） （gradient elution） at a flow rate of 1.0 ml/min， the detection wavelength was 295 nm for levofloxacin hydrochloride and 364 nm for carbazochrome sodium sulfonate， temperature was 30 ℃， and the injection volume was 20 μl. The changes of contents， appearance and pH value of the solution in the mixture were investigated. RESULTS：The linear range was 7.03-80.06 μg/mL for levofloxacin hydrochloride（r＝0.999 5） and 1.70-34.04 μg/mL for carbazochrome sodium sulfonate（r＝0.999 8）；RSDs of precision and reproducibility tests were no more than 2.0％；recoveries were 98.75％-100.63％ and 98.00％-100.83％， and RSDs were 0.65％ and 0.99％（n＝9）， respectively. In normal temperature， the contents of levofloxacin hydrochloride and carbazochrome sodium sulfonate after mixing with 0.9％ Sodium chloride injection within 6 h showed no significant decrease， and the appearance and pH value showed no obvious changes. CONCLUSIONS：The mixing of levofloxacin hydrochloride and carbazochrome sodium sulfonate with 0.9％ Sodium chloride injection in room temperature is stable within 6 h， they can  compatibly use synergistically in clinic.