Two new species of Aristolochia (Aristolochiaceae), A. ledongensis Han Xu, Y. D. Li & H. J. Yang and A. jianfenglingensis Han Xu, Y. D. Li & H. Q. Chen, are described and illustrated from Hainan Island, China. Aristolochia ledongensis differs from the similar A. championii Merr. & Chun and A. bambusifolia C. F. Liang ex H. Q. Wen by having the exterior of the calyx yellow (vs. yellowish green), a smaller basal portion of the calyx tube (15–16 × 4.5–5 mm vs. 30–70 × 7–10 mm), a narrower calyx limb (0.5–0.7 cm vs. 1.5–6 cm wide), and a shorter peduncle (0.7–1 cm vs. 1.8–5 cm). Aristolochia jianfenglingensis differs from the similar A. championii and A. bambusifolia by having the stems glabrous (vs. densely villous), the exterior of the calyx light red-brown (vs. yellowish green), a smaller basal portion of the calyx tube (23–26 × 5–6 mm vs. 30–70 × 7–10 mm), and a narrower calyx limb (0.8–0.9 cm vs. 1.5–6 cm wide). Aristolochia championii and A. bambusifolia have densely villous stems; the exterior of the calyx is yellowish green, with a larger basal portion of the calyx tube (> 30 × ca. 10 mm); the calyx limb is discoid and more than 15 mm wide; and the peduncle is longer than 18 mm. Both new taxa are assessed as Vulnerable (VU D2) according to IUCN Red List criteria.