Lumbar lordosis is defined as the anterior convexity of the lumbar spine in the sagittal plane. Its degree is variable between individuals, affected many other factors. Clinical methods to define lumbar lordosis are Cobb's angle measurement and the angle between extension line of boundary of the first and fifth vertebral body. In this study, the lordotic angle calculated by reflective markers when the three dimensional motion capture system was used compared to the angle calculated from radiography. The coordinates of vertebral body center from radiographic images were digitized. The vertebral body center coordinates from radiographic image and the coordinates from markers were used to calculate lumbar lordotic angle with three different method(ratio method, three point method and curve-fit method). The lordotic angles from radiographic image(θf) were larger than the angles from markers(θ m) in all three methods. The ratio method using radiographic image and the curve-fit method using markers showed the largest coefficient of variance(θf - θm)and the coefficient of variances in all three methods using radiographic image were smaller than using markers. However, the analysis according to Bland-Altiman plot showed a good agreement between both methods(radiography and motion analysis).