Parallel three-dimensional (3D) imaging technique has been widely applied due to its simple configuration and non-vertical parallax.However,the horizonta l parallax obtained is invaria bly negative due to the limitations of the imaging mechanism.As a result,the 3D reproduction of the scene can only be displayed in front of the screen, and the comfortable area behind the screen can not be fully utilized.Moreover, the conversion from the real scene to the stereoscopic images cannot be linear for the parallel camera configuratio n and then the stereoscopic distortions always exist.Therefore,based on the detailed analysis of the cause s,characteristics and impact of the above-mentioned problems using a mathematical model,the horizontal positive pa rallax production and linear distortions elimination schemes are proposed in thi s paper.The c omfortable area and their requirements on the system parameters of the two proposed methods are studied respectively.The proposed m ethod is tested and verified on the self-developed system of 640×480at 120Hz with selection of the CCD resolutions to 752×582.The experimental results confirm the feasibility and rationality of the produ ction of horizontal positive parallax and horizontal negative parallax at the same time and linear distortions elimina tion.It provides a new direction for the actual design of the different applications of the 3D display system.