Abstract: Objective To discuss the classification of obviously asymmetric palpebral fissure of single-fold eyelid and their corrective methods performed with double-fold eyelid blepharoplasty simultaneously. Methods Forty patients with obviously asymmetric palpebral fissure of single-fold eyelid of two eyes were admitted to Linyi People′s Hospital in Shandong province from January 2010 to September 2014, asking for double-fold eyelid blepharoplasty. The preoperative difference of palpebral fissure width between two eyes reached 1.0-2.0 (1.44±0.23) mm. Obviously asymmetric palpebral fissures of single-fold eyelid were divided into three types according to the characteristics of eyelids of two eyes and were corrected by following methods performed with double-fold eyelid blepharoplasty with total incision simultaneously. (1) Twenty-four patients only with different sagging skin of upper eyelids were corrected by resecting sagging skin of eyelids′ margins, and the width of the widest position of resected eyelids′ skin was twice as wide as that of the sagging skin of eyelids′ margins (the same below). (2) Among 6 patients only with different palpebral fissure width, 4 patients whose difference of palpebral fissure width was not bigger than 1.4 mm were corrected by the method of resecting surplus skin, and the width of the widest position of resected eyelids′ skin with narrower palpebral fissure was 1 mm wider than the difference of palpebral fissure width between two eyes (the same below). The other 2 patients whose difference of palpebral fissure width between two eyes was bigger than 1.4 mm were corrected by the method of resecting surplus skin and shortening aponeurosis of levator muscle of upper eyelid. The width of shortened aponeurosis of levator muscle of eyelids with narrower palpebral fissure was 1 mm wider than difference of palpebral fissure width between two eyes (the same below). (3) Among 10 patients with mixing symptoms of sagging upper eyelids skin and difference of palpebral fissure width bigger than 1.0 mm after smoothing sagging upper eyelids′ skin, 7 patients whose difference of palpebral fissure width was not bigger than 1.4 mm were corrected by resecting sagging skin and the method of resecting surplus skin. The other 3 patients whose difference of palpebral fissure width was bigger than 1.4 mm were corrected by resecting sagging skin, shortening aponeurosis of levator muscle of upper eyelids and resecting surplus skin. Palpebral fissure widths of patients were measured during follow-up. Difference of palpebral fissure width between two eyes was calculated and the last difference was recorded. Data were processed with paired sample t test. Results Nine patients who showed incomplete closure of palpebral fissure on the sides of resected eyelids skin or shortened aponeurosis of levator muscle of upper eyelids after operations were treated with erythromycin eye ointment drop in eyes and recovered one week to one month after operations, with no complication of conjunctivitis or keratitis. Double-fold eyelids of all patients who were followed up for 8 to 12 months showed natural shape, smooth lines. No patient showed obvious asymmetry of palpebral fissure between two eyes, and no recurrence of asymmetric palpebral fissure was observed. Difference of palpebral fissure width was 0.1-0.5 (0.19±0.09) mm in the last follow-up, which was obviously smaller than that before operation (t=39.202, P<0.001). Conclusions Obviously asymmetric palpebral fissure of single-fold eyelid can be corrected during the operation of double-fold eyelid blepharoplasty. Patients only with different sagging skin of upper eyelids can be corrected by resecting sagging skin of eyelids′ margins. Patients only with different palpebral fissure width between two eyes can be corrected by the method of resecting surplus skin or combining the method of shortening aponeurosis of levator muscle of upper eyelids. Patients with different sagging skin of upper eyelids and different palpebral fissure width can be corrected by resecting sagging skin of eyelids′ margins and the method of resecting surplus skin or combining the method of shortening aponeurosis of levator muscle of upper eyelids.