A photostable cosmetic composition for protection against UVA and UVB radiations of wavelengths between 280 and 400 nm, which comprises, in a cosmetically acceptable vehicle:(i) at least one UVA-sunscreen agents absorbing predominantly in the UVA-range(ii) at least one UVB-sunscreen agents absorbing predominantly in the UVB-range(iii) at least 0.1% by weight of a 2-hydroxy sulfobetaine of cinnamidoalkyl amine compound.