Abstract: Fiber morphological features of Phyllostachys pubescens coming parts of rhizome at 1-, 3-and 5-year- old were examined by digital light microscopy, and the differences among them were analyzed by Z value two-sided test. The results indicated that the average values of fiber length, fiber diameter, fiber lumen diameter, double-wall thickness, ratio of wall thickness to lumen diameter, ratio of lumen diameter to fiber diameter, and ratio of fiber length to width collected from all P. pubescens rhizome samples were 698.555 m, 21.710 m, 11.375 m, 5.167 m, 0.483, 0.522 and 34.723 respectively. Both fiber length and ratio of fiber length to width were significantly different between 1-and 3-year-old P. pubescens rhizomes, while the difference was insignificant between 1-and 5-year-old P. pubescens rhizomes. However, comparisons between 3-and 5-year-old rhizomes had showed that the differences were significant at 0.01 level. No significant differences were found in fiber diameter and lumen diameter among three ages. When it came to double-cell-wall thickness, ratio of wall thickness to lumen diameter, ratio of lumen diameter to fiber diameter, the difference was significant at 0.05 level for 1-and 3-year- old, significant at 0.01 level for 1- and 5-year-old , and was insignificant for 3- and 5-year-old P. pubescens rhizome. Therefore, fiber morphological features of P. pubescens rhizome meet the qualification as resource of paper pulp, but it still inferior to dicotyledon plants in point view of paper pulp.