Objective:To evaluate the clinical effects of ball attachment and Locator attachment for implant-supported overdenture.Methods:67 cases with edentulous jaw were treated with 150 Straumann and Bego implants and implant-supported overdentures using ball attachments Locator attachments,respectively.All cases were followed up regularly,biological and mechanical complications were observed,the patient satisfaction after restoration was compared between groups.Statistical analysis was performed using SPSS 17.0 software.Results:Follow-up was completed in 58 cases,25 with ball attachment,26 with Locator attachment and 7 with ball changed by Locator.Biological complications comparison showed that the incidence of gingival hyperplasia in the ball group was higher than that in the Locator group(P ＜ 0.05).There was no statistical difference of mechanical complications between the 2 groups (P ＞ 0.05),but the incidence of all kinds of mechanical complications in the Locator group was less than those in the ball group,the average repair frequency of the ball and Locator group was 1.9 times and 0.9 times respectively.Patients'satisfaction on chewing and retention was higher in the Locator attachment group than that in the ball attachment group(P ＜ 0.05).No statistical difference was found in patients' satisfaction between genders (P＞0.05),and no correlation of satisfaction was found with patients' age and follow-up time.Conclusion:The clinical effects of implant-supported overdenture using the Locator attachment is superior to that using the ball attachment.