Background & Aim: Nowdays consumers prefer to eat healthier foods, therefore producers and researchers are involved to improve the variety, quality, taste of food products. Lemon balm is a perennial, aromatic, herb that contains many phenolic compounds. In this research the effect of additing lemon balm powder (by reducing of wheat flour in formulation, instead) on qualities of sponge cakes were investigated.Experimental: Samples were prepared by different addiing lemon balm powder (2.5, 5, 7.5, 10 percent), the control sample was also prepared according to standard sponge cake formulation.then, phenolic compounds amount were analyzed by HPLC.Results & Discussion: The samples contained up to 7.5 percent lemon balm powder had a good acceptance and it could be considered as a food containing more phenolic compound. پرونده مقاله