3-Methylbutanal was obtained by the Strecker reaction with L-leucine and D-ribose at unelevated temperature and acidic conditions. Volatile compounds from reaction systems were analyzed by solid phase microextration (SPME) coupled with gas chromatography-mass spectroscopy (GC-MS). The formation mechanism of 3-methylbutanal was also proposed. Various reaction conditions were investigated, including reaction time, reaction temperature, pH value and salt content of the system. 3-Methylbutanal was obtained by the Strecker reaction with L-leucine and D-ribose at unelevated temperature and acidic conditions. Volatile compounds from reaction systems were analyzed by solid phase microextration (SPME) coupled with gas chromatography-mass spectroscopy (GC-MS) . The formation mechanism of 3-methylbutanal was also proposed. Various reaction conditions were investigated, including reaction time, reaction temperature, pH value and salt content of the system.