The removal of oxytetracycline (OTC) in water by UV, UV/TiO2, UV/Zeolite, and UV/Composite photocatalyst with different ratio was investigated respectively with a 32W lowvoltage mercury lamp. The effects of composite photocatalyst concentration, initial OTC concentration and pH value on degradation were also investigated. It was shown that the UV/Composite photocatalyst with 10% TiO2 and 90% Zeolite was an effective one to remove OTC in water. And in a solution with 50 mg/L OTC in ultrapure water the OTC was removed by 99% within 120 min with the help of 300 mg/L composite photocatalyst. The degradation of OTC by UV/Composite photocatalyst was little influenced by its initial concentration, but influenced by its initial pH. In the environment with pH+2~10, the OTC was removed by more than 95% within 120 min with the help of UV/Composite photocatalyst, when the pH is above 10, the removal rate is rapidly decreased. 