Abstract: Monascus was applied to ferment semi-dried Oninile tilapia , which was obtained with typical fish preserved meat, the aroma of fermented products. Solid phase micro-extraction equipped with PDMS/DVB and gas chromatography-mass spectrometry (GC-MS) was performed in this study to measure volatile compounds of fermented and unfermented tilapia. Results showed that 51 and 75 kinds of compounds were found respectively. Aldehydes and alcohols were most dominant volatiles in fermentation group and more kinds of amines were found. Within these, Nonanal, Octanal, Octanol, 1 -Octen -3 -ol and ethanol were the main flavor sources of fermented tilapia.