Two new aromatic sesquiterpenes, (1-isopropyl-6-methoxy-3-methylnaphthalen-7-yl)methanol (1) and 1-isopropyl-6-methoxy-3,7-dimethylnaphthalene (2), as well as five known ones (3–7) were isolated from the leaves of cigar tobacco. Their structures were determined mainly using spectroscopic methods, including extensive 1D and 2D NMR techniques. Interestingly, the anti-fungi activity test revealed that compounds 1 and 2 showed potential anti-Golovinomyces cichoracearum (the main pathogen of tobacco powdery mildew disease) activity with inhibition rates of 55.4% ± 4.8, and 76.2% ± 5.1 respectively compared with the negative control. These rates are lower than that of a positive control (with an inhibition rate of 90.5% ± 5.3). [ABSTRACT FROM AUTHOR]