There is a growing need to characterize the mechanical properties of single bamboo fibers with their high potential in commercial applications. In this paper, an improved microtensile technique has been applied to measure the tensile strength of fibers isolated from Ma bamboo (Dendrocalamus latiflorus Munro) as an important commercial bamboo species in China. The property variation with respect to the age and locations within a culm was in focus. Ma bamboo fibers had superior stiffness and strength data compared with those of softwood fibers. Four-year-old Ma bamboo fibers are stiffer and stronger than 1-year-old fibers. Their in-trunk variation is rather small both in radial and longitudinal directions. This is due to the relatively constant microfibrillar angle in bamboo culms. Accordingly, the large variations in the bulk mechanical properties of bamboo are mainly attributable to fiber distribution density in the culm rather than the fiber itself.