Objective To compare the clinical effect of three Endobutton plates and clavicular hook plate in treatment of acromioclavicular joint dislocation.Methods Forty-two patients with acromioclavicular joint dislocation were randomly divided into EB group (20 patients) who were treated with three Endobutton plates and CH group (22 patients) who were treated with clavicular hook plate from January 2008 to January 2011.Perioperative index (operation time,blood loss and VAS scores on the third day postoperatively),Karlsson shoulder joint function scores and postoperative complication were compared.Results The operation time and blood loss in EB group were significantly higher than those in CH group [(113.6 ± 25.3)minvs.(62.3±17.8)min,(152.7±15.2) mlvs.(93.1±18.9)ml,P＜0.O5].However,therehadno significant difference for VAS scores on the third day postoperatively between two groups (P ＞ 0.05).EB group was superior to CH group for shoulder joint function scores on the twelfth month postoperatively,but there had no significant difference [95.0％ (19/20) vs.81.8％ (18/22),P ＞ 0.05].The incidence rate of shoulder joint pain and stiffness in EB group were significant lower than those in CH group[20.0 ％ (4/20) vs.50.0％(11/22),20.0％(4/20) vs.54.5％(12/22),P ＜ 0.05].The incidence rate of incision infection in two groups had no significant difference (P ＞ 0.05).Conclusions Compared with clavicular hook plate,three Endobutton plates fixation is complex and consequently with more blood loss.However,three Endobutton plates fixation have advantage in clinical effect and complication.