Nine 5-aryl-2-methyloxazole derivatives were synthesized via gold-catalyzed alkyne oxidation. All of the compounds have been screened for their antiproliferative activities against MCF-7 cell (human breast carcinoma), A549 cell (human lung carcinoma) and Hela cell (human cervical carcinoma) lines in vitro. The results revealed that compounds 1b, 1c and 1d exhibited strong inhibitory activities against the MCF-7 cell lines (with ICso values of 4.6, 9.7 and 2.2 μmol/L, respectively).