In this paper，a new single-component lattice Boltzmann method is proposed to describe liquid-vapor phase transition process. Water and ammonia phase transition process are simulated by using this new model for Redlich-Kwong，Redlich-Kwong Soave and Peng-Robinson equations of state. Compared with the experimental data of water and ammonia，the results show that the Peng-Robinson equation of state is more suitable to describe the phase transitions process of water，ammonia and other substance. In particularly，the simulation results of ammonia with Peng-Robinson equation of state are more close to the experimental data. In order to demonstrate the capability of this model for dealing with two-phase problems，the mass density profile across the interface of water or ammonia which is controlled by Peng-Robinson equation of state are simulated by this model for different temperatures. These simulation results agree with that of classical interface theory. Finally，the relationship between the bubble (droplet) inside and outside pressure difference and its radius is simulated when the bubble (droplet) is in equilibrium environment at different temperatures. The results agree with Laplace law. The surface tension of water and ammonia is obtained from simulation results at different temperature，which agree with experimental data and the critical theory of surface tension.