A porous metal oxide NiO used to adsorb tetracycline(TC) in water samples was synthesized by hydrothermal method and subsequent high temperature calcination.The obtained nanomaterial was characterized by scanning electron microscopy(SEM),Fourier transform infrared spectroscopy(FTIR) and X-ray diffraction(XRD).Results showed that NiO exhibited a clustered flower like porous structure.Effects of pH value,adsorption time,TC concentration and temperature on the adsorption performance of NiO were investigated.The optimal pH value for TC adsorption on NiO was 7.0,and an adsorption equilibrium could be reached in 120 min.The adsorption capacity increased from 26.49 mg/g to 134.84 mg/g when TC concentration varied from 10 mg/L to 100 mg/L.The adsorption process fit well with the pseudo second order kinetic model.The maximum adsorption capacity of NiO for TC was calculated to be 144.90 mg/g by fitting the adsorption date with the Langmuir model.Therefore,with the advantages of reusability,low cost,simple preparation and high adsorption capacity for TC etc.,NiO has a great potentiality in the rapid removal of TC pollutants in polluted water samples.