Greek oregano (Origanum vulgare ssp.hirtum) is an aromatic plant rich in bioactive secondary metabolites which has been used as traditional medicine in Europe.Salicylic acid (SA) is a potent plant hormone which takes part in nearly all plant activities.In this paper, the effects of exogenous SA applications (0.1 and 1 mM) on growth, yield, and secondary metabolite production of Greek oregano were studied.The results showed that both these treatments promote plant growth and weight yield.The total terpene and polyphenolic content in SA-treated plants was higher than control plants based on GC and HPLC results.The low concentration (0.1 mM) treatment had better effects than the high concentration (1 mM) treatment.In addition, both these two SA treatments could induce H2O2 generation in Greek oregano epidermis but with different patterns.Taken together, this study found that SA could elicit Greek oregano growth, biomass yield and secondary metabolite accumulation which are meaningful for Greek oregano production and application.H2O2 may participate in these SA-induced responses in Greek oregano.