Abstract: In this paper, tensile samples of bamboo fiber bundle are successfully dissected from the fiber sheaths of moso bamboo under the aid of a light microscope. The tensile modulus and strength were measured with a microtensile tester consequently. For comparison, samples of single vascular bundles(containing both fiber sheaths and some conductive tissues)and bamboo slivers with different fiber contents were also fabricated and tested. The tensile modulus and strength of the fiber bundles were 42.72 GPa and 729.25 MPa, respectively, located between the values obtained by the latter two methods. The result also agreed well with several published reports, which indicated the prepared bamboo fiber bundles could well represent the real performances of bamboo fiber sheaths. The present paper not only proposed a well-established key methodology for studying the mechanical behaviors of bamboo at microscopic scale, but also provided basic data for the development of bamboo fiber bundles reinforced polymer composites and the multiscale simulation of bamboo mechanical behavior.