Abstract: The effects of longitudinal constant tensile loads on transverse behaviors and transverse loads on longitudinal behaviors of a single ply of nylon cord-rubber composite are studied respectively under biaxial tensile condition with cruciform specimens in this paper. Experiment results indicate that the effects of longitudinal constant tensile loads on transverse tensile behaviors are obvious. Transverse stress-strain behaviors change largely compared with uniaxial transverse tensile behavior; transverse tensile strength increases first and then decreases; fracture strain and deformation energy decrease by increasing of longitudinal tensile loads; the results are induced by common actions of rigidification and damnification caused by longitudinal tensile loads. However, the effects of transverse constant tensile load on longitudinal tensile mechanical behavior are not distinctive. It can be ascribed to large discrepancy between longitudinal and transverse properties of nylon cord-rubber composite.