The physical properties and intrinsic defects of YPO₄ crystal were studied by computer simulations with the GULP software.The calculated results show that the crystallographic data coincide well with the experiment results by using the existing potential parameters.The relaxed fitting strategy shows the YPO₄ crystal has the most energy of strain resistance in c axis.The thermodynamic calculations and results show the contribution of the vibrational entropy to the intrinsic point defect formation energies can not be ignored under high temperature.The calculated results of defect formation energies indicate that the oxygen vacancy and the oxygen Frenkel disorders are formed more easily.