The dynamic behavior of atoms in simple liquid binary mixtures is analyzed by molecular dynamic simulation. Time correlation functions between the initial velocity of a tagged particle and latter velocities of neighboring particles are calculated for soft-sphere liquid mixtures of species with different mass and/or size. The transfer of momentum from a tagged particle to its neighbors as well as the differences between the velocity cross correlation between particles of the same or different species is discussed. (C) 2001 American Institute of Physics.