Our previous study on proteomic analysis has shown that clusterin (CLU) is significantly decreased in the cerebrospinal fluid (CSF) of patients with epilepsy. Therefore, the present study aimed to confirm CLU concentration reduction in the CSF of patients with drug-resistant epilepsy and drug-responsive epilepsy. Fifty-two patients with epilepsy (23 drug resistance and 29 drug effectivity) and 20 control individuals were recruited. The concentrations of CSF and serum CLU were detected. Moreover, alteration of CLU was detected in the rat hippocampus over time after pilocarpine-induced status epilepticus (SE). Our results showed that human CSF-CLU levels were decreased in patients with both drug-resistant epilepsy and drug-responsive epilepsy compared to controls, and concentration of CSF-CLU was obviously lower in drug-resistant epilepsy than in drug-responsive epilepsy. In the pilocarpine-induced seizure rats, expression of neuronal CLU was gradually decreased in a time-dependent manner from acute phase to chronic phase after the onset of SE. In conclusion, CLU level is decreased in the CSF of human epilepsy and the similar alteration is confirmed in a rat model with epilepsy. Therefore, CLU might contribute to the development of epilepsy and be a potential CSF biomarker for resistant epilepsy.