Based on the reference [4], a dipole amplitude-squared operator of a three-level atom is defined, and a dipole amplitude-squared squeezing of a three-level atom is also given with the uncertainty relationship of Hessenbery. The dipole amplitude-squared squeezing effects of a threelevel cascade atom interacting with a correlated two-mode squeezed vacuum field are investigated. Based on the numerical calculations, the influences of the squeezing parameters of the initial squeezed state field, the frequency detuning value of the mono-photon and the intensity of atomfield co...