AIM:To compare the biometry measurements of IOL-Master and A-scan ultrasound in patients with cataract surgery,and analyze its clinical significance.METHODS:Dynamic observation was conducted in 84 eyes of 70 cataract patients by same operator.Measurements were made before and 14 days after the operation by IOL-Master optical instrument(Carl Zeiss)and Ultrascan Digital 2000 contact ultrasound A-scan(Alcon),respectively,which included axial length(AL),anterior chamber depth(ACD),and crystal thickness.Simultaneously,a prospective comparison of measurements was made by A-scan ultrasound in sitting and decubitus position.RESULTS:ACD:(1)Average depth of postoperation increased by 28.41% compared with that before operation.The operational devation of ACDs was correlated with crystal thickness positively(r=0.396,P=0.002,n=58),Linear analog representation showed that the operational devation of ACD=0.445×crystal thickness-1.207(mm);(2)There was no statistical significance of ACDs before and after operation measured by A-scan ultrasound in sitting and decubitus position(P=0.264,n=57;P=0.663,n=44);(3)The preoperation ACD values measured by the IOL-Master was deeper than that measured by A-scan ultrasound(P<0.01,n=29),mean value by A-scan ultrasound:2.75±0.57mm,mean value by the IOL-Master:2.96±0.61mm,difference in values was-0.21±0.29mm,95%CI:(-0.32-0.10mm);(4)The postoperation ACD values given by the IOL-Master was deeper than that by A-scan ultrasound(P=0.002,n=41),mean value by A-scan ultrasound:3.46±0.46mm,mean value by the IOL-Master:3.79±0.65mm,difference in values was-0.33±0.63mm,95%CI:(-0.53-0.14mm);(5)There was no statistical significance of ACD changes before and after operation measured by A-scan ultrasound and IOL-Master respectively(P=0.619,n=19).AL:(1)The ALs before and after operation were not significantly different(P=0.079,n=58);(2)Before and after operation,the difference of AL values measured by A-scan ultrasound in sitting and decubitus position both were not significant(P=0.934,n=57;P=0.196,n=44);(3)Before and after operation,the difference of AL values measured by the IOL-Master and by A-scan ultrasound both were not significant(P=0.175,n=17;P=0.248,n=31).CONCLUSION:The postoperative average depth increased by 28.41% than preoperative,and the operational devation of ACDs was correlated with crystal thickness positively.The biometry measurements of IOL-Master and A-scan ultrasound in patients with cataract surgery was same except ACDs.In addition,different measuring positions have no influence on the result of A-scan ultrasound measure.