Objective: To explore the characteristics of cognitive function in depressive patients with or without suicide ideation.Methods: There were 135 patients with major depression and suicide ideation and 326 patients with major depression but without suicide ideation recruited in this study (diagnosed according to DSM-Ⅳ).184 normal cases matched with the total patients in these aspects--age, gender were selected as normal control.Repeatable Battery for the Assessment of Neuropsychological Status (RBANS) and Stroop Colour Test were used to evaluate cognitive function.Results: Comparing with normal control, depressive patients showed significant cognitive function impairment for both patients with and without suicide ideation.In RBANS test, the scores of immediate memory, story repeat, vocabulary study, vision scope, linguistic function, numeral scope, attention and delayed memory were significantly lower in depression patients group than those in normal control.In Stroop Colour Test, the time required for completing the homochromatic colour, both word, both colour in depression patients were significantly longer than the control group (P<0.05).There were significant difference in item recall and item vocable time among the three groups.For depressive patients with suicide ideation, the recall score is lower (21.18±8.15) than that in patients without suicide ideation (23.19±8.38) and normal control (29.78±8.61) (P<0.05); and the vocable time is longer (14.84±6.59) in patients with suicide ideation than patients without suicide ideation (13.74±5.15) and normal control (12.50±3.29) (P<0.05).Conclusion: Depressive patients commonly suffer from comprehensive damage of cognitive function, such as memory, attention, and executive function.For patients with suicide ideation, the impairment of cognitive function of memory and executive function were considerably serious.