Abstract: The total particulate matter (TPM) on Cambridge pad was extracted with CO₂ free water and the pH value of aqueous extraction was measured by pH meter. The pH values of TPM of cigarettes containing single tobacco (including flue-cured, burley, oriental tobacco) and some commercial brands of cigarettes (including domestic Virginia type, British Virginia type and American blended type) were determined. The results showed that smoke pH values of single tobacco cigarettes were in following order: burley > oriental > flue-cured. To the commercial brands, the order of smoke pH values were American blended type > British Virginia type > domestic Virginia type. Sugars, organic acids, inorganic acids, amino acids, alkaloids, salts and phenols were added to control cigarettes respectively. The great reduction of the pH values of TPM of the cigarettes spiked with lactic acid and sucrose was found, while the pH values of the same were significantly increased by addition of nicotine. The pH values of some commercial brands of cigarettes were also given.