An investigation of EtOAc extracts of Kadsura coccinea (Lem.) A. C. Smith, has led to the isolation of two new compounds characterized as 3-hydroxy-12-hydroxyl coccinic acid (1) and 3-hydroxy-neokadsuranic acid A (2). Their structures were established by 1D and 2D NMR techniques and mass spectroscopy. Antiproliferative effects of the isolated compounds were evaluated against four human tumor cell lines (A549, HCT116, HL-60 and HepG2), and it was found that compound 1 exhibited antiproliferative effects with $IC_{50}$ values ranging from 3.01 to 18.08 ${mu}g$/mL.