Abstract: Experimental study shows that the transverse tensile strength of fiber bundle/epoxy resin composites specimens has a good correlation with the transverse tensile strength of unidirectional laminate specimens. However, there is a discrepancy in values obtained using the two testing methods. In this paper, three types of fiber bundle/epoxy resin composites and unidirectional laminates were prepared using two kinds of carbon fibers and epoxy resins. Based on the measured transverse tensile strength of fiber bundle/epoxy resin composites and unidirectional laminates, as well as the tensile strength of epoxy matrices, a strength model was established to bridge the transverse tensile strength of fiber bundle/epoxy resin composite and unidirectional laminate. The parameters in the model were fitted according to the experimental results of two types of fiber bundle/epoxy resin composites and unidirectional laminates. Then the model was verified using the third type of fiber bundle/epoxy resin composite and unidirectional laminate. It is found that the predicted transverse tensile strength of the unidirectional laminate agrees well with the measured value, with relative deviation of 9%. Therefore, the proposed method can be employed to predict the transverse tensile strength of unidirectional laminates with simple tensile tests of fiber bundle/epoxy resin composites and epoxy matrices.