Nowadays, laser 3D printers are one of the efficient devices for rapid prototyping process. There is vast number of studies about quality of samples in these printers. The laser sintering technique is the one of the popular method for consolidation and shaping of semi-crystalline polymer powders. In this study, we considered the role of laser parameters included laser scanning pattern, laser scanning speed and power in tensile strength and stiffness as the important factors of the mechanical property of samples which are sintered by laser in single layer procedure. Experimental samples were sintered with low power CO2 laser on Polypropylene powder with 200 micrometer grain size. Tensile strength and stiffness had been measured according to ASTM D882 standard and results were reported eventually. In this paper, main effects of factors and interactions were considered via the variance analysis under the imperative conditions that have been passed before. The regression equation was derived finally. A general full factorial method was employed as experimental design. The results show that the laser scanning pattern and laser power have most effects on tensile strength and stiffness of produced samples. The maximum value of responses, 2/9 MPa for mechanical strength and 96 N/mm for stiffness, demonstrate that the 2W power of laser with 1650mm/min of scan speed can be the proper value to obtain an optimal response when the selected pattern is No2.