To prepare and quantitativeey determine of frozen-dried supporting agent are screened based on Lomefloxacin aspartate for injection, the kinds and quantity the external appearance and the quality, and the contont of lomefloxacin aspartate is determined by ultraviolet spectrophotometry. The resuts show that glucose 50% is used as frozen-dried supporting agent. The content of lomefloxacin aspartate is 99% as labelled. The preparation technics is appropriate and the determination method is simple and feasible. The prepared frozen-dried injection is able to meet both the pharmaceutical and clinical requirements.