To experimentally study the influence of pin's angle and diameter and pin materials on the strength and modulus of X-cor sandwich structures,the specimens of flatwise tensile test were made of the Rohacell 31 foam core and the pins with different kinds of diameter consisting of T300/FW-63 carbon/epoxy and SC-240/FW-63 glass/epoxy with pultrusion process.The results show that the efficiency of pin reinforcing flatwise tensile strength of X-cor sandwich structures increased first and then decreased as pin's angle increased and increased as pin's diameter decreased,the efficiency of pin reinforcing flatwise tensile modulus of X-cor sandwich structures decreased as pin's angle increased and decreased as pin's diameter decreased,the efficiency of pin reinforcing flatwise tensile strength of X-cor sandwich structures is keep constant with different pins materials,but the efficiency of pin reinforcing flatwise tensile modulus of X-cor sandwich structures is higher with higher modulus pins.