AIM:To analyse the effect of weakening inferior oblique muscles on the status of ocular torsion by measuring disc-fovea angle (DFA). METHODS:A total of 30 eyes of 23 cases with inferior oblique muscle overaction underwent inferior oblique weakening procedures,images of fundus including fovea and disc were photoed by OCT before and one week after surgery. DFA was measured by using PhotoShop software, and statistical analysis was done with SPSS software. RESULTS:DFA was 17.200°±6.624°and 7.735°±6.545°respectively before and one week after surgery. There was significant difference for DFA before and one week after surgery (P<0.01). CONCLUSION:DFA can be changed significantly through inferior oblique weakening procedures. Measurement of DFA is useful in surgery design before surgery and surgical result evaluation after surgery.