Four new 2-arylbenzofuran derivatives, cathafurans A (1), B (2), C (3), and D (4), were isolated from the stem bark of Morus cathayana. Their structures were determined by spectroscopic methods. Compounds 2 and 3 exhibited moderate activities against five human cancer cell lines, with IC(50) values ranging from 6.17 to 9.60 microg/mL.