Some metabolites and embryo growth of primed tobacco (Nicotiana tabacum L. cv. ‘KFI09’) seeds were observed during priming. The seeds were primed at 15 and $25^{circ}C$ for 1, 2, 3, 5, 10 and 15 days in a -0.8 MPa polyethylene glycol 6000 (PEG) solution. The time to 50% seed germination (T$_{50}$) was greatly reduced when the seeds were primed at $25^{circ}C$ when compared with 15$^{circ}C$. The $alpha$-amylase activity and sugars and amino acid contents in the seeds primed at $25^{circ}C$ greatly increased, while $alpha$-amylase activity was similar, and sugar and amino acid contents increased slightly in the seeds primed at 15$^{circ}C$. When the seeds were primed at $25^{circ}C$, growth of the embryo which was enclosed by endosperm was detected, while the endosperm became thinner as the priming duration was extended.d.