Objective To assess the effects of insulin resistance and secretion levels on the cognitive function in patients with schizophrenia， and to explore the correlation between the insulin resistance and secretion level and the clinical symptoms. Methods Totals of 193 inpatients with schizophrenia（ 113 males， 80 females） were enrolled， including 68 patients with insulin resistance and 125 patients without insulin resistance， while 78 patients with normal pancreas islet cell function and 115 patients with reduced pancreas islet cell function. The Repeatable Battery for the Assessmental of Neuropsychological Status（ RBANS） and the Stroop Colour Word Test（ SCWT） were used to assess the patients’ cognitive function. And the Positive and Negative Syndrome Scale（ PANSS） was used to assess the patients’ psychotic symptoms. The insulin and fasting blood-glucose levels were detected by chemiluminescence immunoassay and automatic biochemical analyzer. Results The insulin resistance group had fewer errors in the card 1 and 2 of SCWT and higher scores in digit span and list recognition of RBANS compared with non-insulin resistance group（ P ＜ 0.05）. The normal pancreas islet cell function group had less errors and time in the card 1 and 2 of SCWT and higher scores in figure copy， line orientation， digit span， coding test， attention score， story recalled score compared with abnormal pancreas islet cell function group（ P＜0.05）. A negative correlation was found between the insulin resistance index and the PANSS scores（ r=-0.139，P＜0.05）. No correlation was found between the pancreas islet cell function and the clinical symptoms. Conclusions The insulin resistance group may have better cognitive function compared with the non-insulin resistance group. The normal pancreas islet cell function group has better cognitive function compared with the reduced pancreas islet cell function group. A negative correlation was found between the insulin resistance index and the PANSS scores.