In this paper we study the atom dissipation effect in a laser cavity.The cavity field mode is described by the FoxLi quasimode due to the leakiness of the cavity.Our results show that the atom decay rate versus the decay rate of the quasimode is a Lorentz type.Effects of the atom-cavity detuning as well as cavity size are also discussed. In this paper we study the atom dissipation effect in a laser cavity. Cavity field mode is described by the FoxLi quasimode due to the leakiness of the cavity.Our results show that the atom decay rate versus the decay rate of the quasimode is a Lorentz type.Effects of the atom-cavity detuning as well as cavity size are also discussed.