The formula(ofloxacin 3.0g,diluted acetic acid solution qs,glycerin 200 ml,70%alcohol to 1000 ml),method of preparation,and quality control of ofloxacin ear-drops were de-scribed.The stability of ofloxacin ear-drops was studied primarily by using the initial average ratemethod.The shelf-life of ofloxacin ear-drops at 25℃ was 6. 55 years。