The dynamics characteristic and effect of plasma play an important role in films growth process of pulsed laser deposition (PLD).In this paper,based on the consideration of local conservations of mass,momentum and particle ionization of plasma,collected as the assumption that plasma can be viewed as compressible ideal fluid and high temperature-high pressure ideal gas,we developed a new dynamics expansion mechanism for plasma produced by pulsed laser radiation.Using analytical method,the space number density and pressure evolvement of plasma in cylindrical coordinate are obtained,the dynamics evolvement equations are derived too.The results from the present model indicate that the plasma dynamic expansion behavior can be evidently influenced by the ionization fraction η.Its effect is similar to a new dynamic source for plasma expansion and increase the expansion acceleration in all directions.The predictions of the expansion of the plasma is affected by the temperature,the average atoms mass,the ionization degree and the dimension of the plasma are consist with the experimental observation.