Ladar and CCD camera have the excellent ability of capturing 3D information of objects, and they are widely used in 3D modeling. The major problem of the fusion of ladar data and CCD camera data is the coordinates calibration between them. In consideration of the traits of ladar and CCD camera, a special 3D calibration object is designed, and an improved coordinates calibration method is proposed, which fits a plane by using principal components analysis and can highly improve the calibration precision. The improved coordinates calibration method is applied on the 3D reconstruction and texture mapping. Experiment results show that our algorithm gives good result in texture mapping.