Chemical investigation of the 90% acetone extract of the branches and leaves of Sabina gaussenii led to the isolation of two new cinnamyl isovalerate derivatives (1-2) and eighteen known compounds (3)(4)(5)(6)(7)(8)(9)(10)(11)(12)(13)(14)(15)(16)(17)(18)(19)(20). Their structures were determined mainly by means of MS, 1D-and 2D-NMR data, and this is the first time these compounds have been reported from this plant. The biological activity test results indicated that the 90% acetone extract showed cytotoxicity against the human lung adenocarcinoma (A549) cell line (IC 50 = 0.98˘0.1 µg/mL), compound 6 showed cytotoxicities against human cervical carcinoma (HeLa) (IC 50 = 0.4˘0.1 µM ) and human gastric carcinoma (BGC-823) (IC 50 = 0.9˘0.2 µM) cancer cell lines, and compound 19 showed cytotoxicities against HeLa (IC 50 = 1.5˘0.4 µM), BGC-823 (IC 50 = 7.0˘0.8 µM ), and A549 (IC 50 = 10.6˘1.5 µM ) cancer cell lines.