Objective To investigate the effects of ziprasidone and chlorpromazine on the ECG and cognitive function of patients with first episode of schizophrenia .Methods According to the digital table ,90 patients with first-episode schizophrenia were divided into two groups ,45 cases in each group .The control group was given chlorproma-zine,while the observation group received oral ziprasidone .Clinical efficacy,cognitive function and ECG results were compared before and after treatment .Results The PANSS scores of the study group and the control group were (57.78 ±4.16) points and (58.43 ±4.33) points after treatment,which were significantly lower than (72.62 ± 4.66)points and (72.39 ±4.87)points before treatment (t=7.15,7.46,all P〈0.05),but the differences were not significant between the two groups (all P〉0.05).The total number of tests of WCST ,continuous errors and CT error rate in study group after treatment were (73.32 ±5.08),(40.35 ±4.15) and (12.72 ±2.00)%,which were signif-icantly lower than (86.43 ±5.58),(67.72 ±4.26) and (21.02 ±2.33)%before treatmemt and (84.32 ±5.16), (65.82 ±4.25) and (20.05 ±2.20)%in the control group(t=6.84,7.21,7.85,7.52,8.21,8.12,all P〈0.05). WCST categories completed and the number of CT net scores were (5.32 ±0.40) and (125.83 ±11.65) points, which were significantly higher than (3.41 ±0.38) and (102.82 ±10.72) points before treatment and (3.52 ± 0.39) and (108.37 ±10.24)points in the control group,the differences were statistically significant (t=6.72,7.11, 7.01,7.53,all P〈0.05).The incidence rate of abnormal ECG in study group was 22.22% after treatment,which was significantly lower than 55.56% in the control group(χ2 =11.02,P〈0.05).Conclusion Ziprasidone and chlorpromazine have a equivalent efficacy in the treatment of first-episode schizophrenia ,but ziprasidone can signifi-cantly improve cognitive function and has little effect on ECG ,it is safe. Key words: Schizophrenia; Ziprasidone; Chlorpromazine; Electrocardiography; Cognition