AIM:To evaluate the correlation among the blood sugar,acute inflammation before phacoemulsification and posterior capsule opacification (PCO) in diabetes cataract. ·METHODS:According to the different ranges of blood sugar before the phacoemulsification,46 patients with diabetes mellitus(DM) were dividing into 2 groups. 22 patients in group 1,with the blood sugar(BS) <8.5mmol/L,average (8.04±0.54)mmol/L;24 patients in group 2,with the BS >8.5mmol/L,average(12.26±0.80)mmol/L. The degree of acute inflammation,the incident rate of pupillary fibrin membrane in 1 week and the onset rate of POC 6 months after the surgery were compared. ·RESULTS:The average degree of inflammation in group 1 was (1.27±0.46),and disappeared in (5.18±0.96) days; while in group 2,the average degree of inflammation were (1.33±0.48),and disappeared in (5.21±1.29) days. There were no significant differences between the average degree of inflammation,the incident rate of pupillary fibrin membrane and PCO. ·CONCLUSION:Patients with poor sugar controlled can undertake the phacoemulsification when the blood sugar is around 13.0mmol/L without serious complications.