BACKGROUND:: Traditional pulmonary functional imaging techniques have great inconvenience. Using the ventilation information in four-dimensional computed tomography to rapidly obtain the pulmonary functional imaging has important value for the diagnosis and treatment of lung diseases. OBJECTIVE:: To investigate the feasibility of getting the pulmonary ventilation imaging distribution based on paired four-dimensional computed tomography images at the peak-exhale and peak-inhale phases by means of three-dimensional deformable image registration. METHODS:: The computed tomography data of thoracic undergoing free breathing were acquired in Cine mode, and the previously developed four-dimensional computerized tomography software was used for the four-dimensional reconstruction. Computed tomography images at the peak-exhale and peak-inhale phases were obtained, the process of lung segmentation, three dimensional image registration based on deformable image registration algorithm, and quantization analysis of three-dimensional pixel displacement vector were in progress, and the regional ventilation images were obtained finally. RESULTS AND CONCLUSION:: By means of three-dimensional deformable image registration, the goal that extracting pulmonary ventilation images include transverse, coronal and sagittal based on paired four-dimensional computed tomography at the peak-exhale and peak-inhale phases was realized.(Figure is included in full-text article.)