A large number of tetracycline antibiotics were detected in the environment which posed a serious threat to ecosystems and human health. Carbon-based catalyst-activated peroxymonosulfate (PMS) technology has received extensive attention due to its environmental friendliness and no secondary pollution, but its catalytic oxidation efficiency needs to be further improved. In this paper, peroxymonosulfate (PMS) were activated by carbon nanotubes (CNTs) calcined at different temperatures for degradation of tetracycline (TC) in water, and the effects of PMS concentration, CNT dosage and initial pH on the degradation of tetracycline were investigated in detail. The results showed that the CNTs calcined at 950 ℃ exhibits the best performance on the PMS activation. When the initial pH was 9, the dosage of CNTs was 0.4 g/L, and the molar concentration ratio of PMS to TC was 20:1, the TC degradation is the highest.