·AIM:To observe the effect of anterior transposition of the inferior oblique muscle on dissociated vertical deviation(DVD)with inferior oblique muscle overaction.METHODS:A total of 8 cases 11 eyes diagnosed as DVD with inferior oblique muscle overaction were observed in this study.The inferior oblique muscle was transposed to 2mm anterior or in line with the temporal border of the inferior rectus insertion in all patients;the horizontal rectus muscle was operated on for horizontal strabismus in 5 cases.RESULTS:The inferior oblique muscle overaction was eliminated in all cases,6 eyes with 1+ and 2 of 3 eyes with 2+ degree of DVD had no evidence of DVD,1 of 3 eyes with 2+ and 1 of 2 eyes with 3+ degree of DVD had 1+ degree of DVD,1 of 2 eyes with 3+ degree of DVD had 2+ degree of DVD.CONCLUSION:Anterior transposition of the inferior oblique is an effective method for DVD with inferior oblique muscle overaction and no side effect has been observed.