Two species of bamboo, Phyllostachys edulis and Phyllostachys aureosuleata (including 4 cultivars for each of the species) are known to have significant amounts of phenols and flavonoids, and exhibit a strong antioxidant activity. Experiments were conducted to examine the variation in the contents of total phenols and flavonoids, and antioxidant activities in the shoots and shells. The result showed that the hightest contents of total phenols and total flavonoids were P. aureisykeata cv. Spectabilis and P. edulis cv. Heterocycla, respectively. The antioxidant activities were determined by DPPH(scavenging assays of DPPH radicals). Among all of the shoots samples analyzed, the P. aureisykeata cv.Spectabilis showed the best performance in scavenging assays of DPPH radicals. Among the shells, the P. edulis cv. Heterocycla showed the best performance. In addition, significant correlations were found between the contents of total phenols and flavonoids and DPPH radical scavenging activity. This work indicated that ethanol extracts of shoots and shells from eight cultivars bamboo exhibited stronger antioxidant activities compared with those of the commercial compound (Trolox). It might be considered as a potential rich sources of natural antioxidants.