In this paper,we have investigated a system that is composed of a ∧-type three-level atom and a ∨-type three-level atom with a single-mode photon field.Under the initial state of one atom is exticed state and the other one is in the ground state,the evolution of the state vector of the system is delivered.The entanglement between atoms is described by using the negative eigenvalues of the partially transposed density matrix,the effects of the interatomic dipole-dipole interaction strength and photon number on the atoms entanglement evolution are analyzed by means of numerical calculation.The results show that: The interatomic dipole-dipole interaction enhances entanglement between atoms,while photon number decreases entanglement between atoms.