Based on the specimens collected from Thailand and preserved in AAU. BKF C, and KYO, Campylandra siamensis (Convallariaceae, Liliaceae s.l.) is newly described in this paper. This species is similar to C. chinensis (Baker) M.N. Tamura. S. Yun Liang & Turland. but differs from it in having numerous sessile leaves. longer while bracts. longer perianth tube and larger pistil.