Objective To understand the clinical characteristics and outcomes of electrocardiogram（ECG）abnormalities induced by Olanzapine in children. Methods Medical records of patients who had hospitalized in Department of Childhood Psychiatry，Urumqi Fourth People’s Hospital and treated witholanzapine for the first time from June 2012 to June 2016 were collected and retrospectively analyzed. Theincidence，characteristics，treatments and outcomes of ECG abnormalities were analyzed. Results A total of 198 patients were enrolled into this study. The total incidenee of ECG abnormalities was 57.07% and thedifference between the low dose and high dose groups was statistically significant（P＜ 0.01）. The incidences in the 1，2 and 3 months were 53.98%，24.78% and 21.24% respectively. There were statistical significancebetween the low dose and high dose groups in the 1，3 months （P＜ 0.05）. No statistical significance was found in abnormal ECG between olanzapine high dose and low dose groups after double and triple combinations （P＞ 0.05）. The main characteristics of abnormal ECG induced by Olanzapine were sinus tachycardia，ST-T changes， T wave changes and sinus arrhythmia，etc. The clinical symptoms were completely relieved after dressing change and symptomatic treatment in 133 patients. Conclusions Sinus arrhythmia，ST-T changes and T wave changes are more common in ECG abnormalities caused by Olanzapine. ECG abnormalities are related with the dosage， and could return entirely to normal after proper treatment.