Abstract: The formation of copper excited state4d′4F9/2 and its transition in the copper plasma induced by laser are studied by the time-resolved spectra technology. The experimental results indicate that the formation of excited state4d′4F9/2 follows different mechanisms, such as recombination of electrons and ions, collision between the elemental species and self-absorption of atomic lines, during the evolution of plasma. When the collision between particles is severe, the excited state4d′4F9/2 transits to low energy states4p′4Do7/2 and4p′4Fo9/2 with the same probability. After 500 ns of plasma radiation, the collision becomes weak, and the excited state4d′4F9/2 mainly transits to4p′4Do7/2 with emitting the characteristic line Cu Ⅰ 359.91 nm.