¹ SamiaZaroog  Ahmed, ² MoustafaAbdouElsyad,  ³ EL sayedAbdElkhale ¹ BDS , faculty of dentistry ^,zliten University, libya ² Assistant professor of removable prosthodontics, faculty of dentistry,  Mansoura University. ³Lecturer of removable prosthodontics, faculty of dentistry, Mansoura University Abstract: Statement of problem: excessive of occlusal overload is applied to the implant may cause pathologic stresses and strains in the crestal bone stimulating resorption which influences by type of attachments used Aim of work: was evaluated of the effect of strain around implants supporting maxillary overdentures with different attachments. (Milled bar, Telescopic and Locator attachments). Material and methods: The In-vitro study was carried out on acrylic resin model representing maxillary completely edentulous with four analogous four implants installed at both canine and second premolar areas by using guide template. Then silicone auto-polymerized soft liner material was prepared for covering ridge and palatal area. Fifteen experimental maxillary over dentures were fabricated over the model and connected to the implants with: Group I: rigid telescopic attachments (TA) Group II: milled bar attachments (MB), and Group III: Locator attachments (LA) A liners of Strain gauge were connected to implants.  Data was collected and statistically analysis using Shapiro-Wilk test identify the normal distribution. Result: During bilateral loading: TA recorded the higher total strain values (41.125) followed by MB (18.450) and the LA (12.500) recorded the lowest value. While during unilateral loading: TA also recorded higher strain values (122.50), and MB/LA recorded the lowest value (14.625/15.125) (without significant difference). In both loading: Canine implants recorded higher microstrain values than premolar implants. Also Buccal/loading and Palatal/loading strain gauges recorded the highest strain(without difference) followed by Buccal/non-loading and Palatal/non-loading recorded the lowest strain. Statistically there was differ significantly implant positions, and strain gauge position. (3 way ANOVA, p=.00) Conclusion:It could be concluded that: Locator attachments are were associated with reduced      peri-implant strain compared to telescopic or milled bar attachments.