Objective To explore the effects of propofol and thiopental sodium injection on convulsive seizure in electro-convulsive therapy(ECT) and to provide evidence to help the selection of intravenous anaesthetics in improved ECT. Methods Total of 111 patients who received ECT in the 3rd Pepole’s Hospital of Panzhihua from July to December 2005 were divided into a thiopental sodium group (n =62) and a propofol group (n =49). These patients received intravenous anaesthesia with suxamethonium plus thiopental sodium or propofol for the implementation of ECT, respectively. The status of convulsive seizure was compared between the two groups. Results There were no significant differences between the two groups in terms of main demographic data, disease category and ECT parameters (Pgt;0.05). Motor seizure and electricity discharge lasted significantly longer in the propofol group than in the thiopental sodium group (Plt;0.01). Conclusion Thiopental sodium can increase the excitation threshold of brain cortical neurons and decrease the level of convulsive seizure induced by ECT. Propofol may decrease the excitation threshold, and increase the level of convulsive seizure under the same ECT parameters, but may have the potential to induce epileptic seizure.