OBJECTIVE： To compare the effects of aripiprazole and quetiapine on cognitive function in patients with bipolar depression. METHODS： 100 patients with bipolar depression were selected and randomly divided into aripiprazole group and quetiapine group， with 50 cases in each group. Aripiprazole group  was given aripiprazole 5 mg， bid； quetiapine group was given quetiapine 25 mg， bid， on 1st-3rd day， increasing 25 mg every 3 days until to 150 mg， bid. Both groups received 8 weeks of treatment. Before and after 2， 4， 6， 8 weeks of treatment， MADRS， MoCA， MMSE and ADL of 2 groups were recorded. RESULTS： There was no statistical significance in MADRS between 2 groups after 8 weeks of treatment （P＞0.05）. MoCA of aripiprazole group was higher than that of quetiapine group after 2，4，6 and 8 weeks of treatment， with statistical significance （P＜0.05）. After treatment， MMSE and ADL of 2 groups were improved significantly compared to before treatment； MMSE of aripiprazole group was significantly higher than that of quetiapine group while ADL was significantly lower than quetiapine group after 8 weeks of treatment， with statistical significance （P＜0.05）. CONCLUSIONS： Quetiapine and aripiprazole has obvious curative effect on patients with bipolar depression， and the improvement effect of aripiprazole is better than quetiapine on cognitive function in patients with bipolar depression.