Unquenched Effects and Quark Mass Dependence of Lattice Gluon Propagator in Infrared Region

In this paper,the gluon propagator in Landau gauge has been studied on a lattice,including the quenchedand the unquenched one.The small geometry size of lattice we use is 16;×32,and the big one is 20;×64.For thequenched approximation,we fit the numerical results and give a little different fitting values.We also obtain unquenchedeffects by comparing the gluon propagator resulting from the quenched and unquenched configurations,for both thetwo-flavor and three-flavor cases.For the unquenched configurations,an obvious quark mass dependence has not beenfound in the small quark mass ease,but is found in the three-flavor case when the quark mass is big.