  The J/Psi cross section ratios of p-A/p-p under different collision energy is
calculated with cold nuclear matter effects redefined in this paper. The
advantage of these new definitions is that all cold nuclear matter effects have
clear physical origins.The radios are compared with the corresponding
experiment data and that calculated with classic nuclear effects. The ratios
calculated with new definitions can reproduce almost all existing J/Psi
measurements in p-A collisions more accuratly than that calculated with classic
nuclear effects. Hence, this paper presents a new approach to explain cold
nuclear effects in the hardproduction of quarkonium.
