The UV-Vis spectra of bamboo exhibit a main absorbance between 250 and 400 nm (Supplementary Fig. ). Moreover, upon excitation, bamboo shows fluorescence at 435 nm (Fig. ) and long-lasting RTP emission at 480 nm, with lifetime of 90.4 ms (Fig. and). These observations prompted our present inquiries to explore bamboo-based RTP fibers. Treatment with peroxyacetic acid (Fig. and Supplementary Fig. ) was effective in partially removing hemicelluloses and lignin, unraveling the "B-fibers", which were analyzed by comparing their NMR spectra with that of natural bamboo (Supplementary Fig. ). The cellulose, hemicellulose and lignin content in B-fibers were determined to be 85.8%, 6.1% and 1.1%, respectively (these components amounted to 58.3%, 14.5% and 23.8% in the unmodified bamboo). The B-fibers showed a high mechanical strength (tensile strengthen and Young's modulus of ca. 424 MPa and 22 GPa, respectively), making them stronger than cotton and silk fibers (Supplementary Fig. ). The B-fiber system exhibited RTP emission (Fig. ), with a lifetime of 294.9 ms (excitation wavelength = 270 nm), surpassing the original bamboo (Supplementary Fig. ). To test whether the proposed strategy can be expanded to other bamboo species, B-fibers were obtained from other sources.