[en] Effects of graviton mass on the Joule-Thomson expansion process of neutral AdS black holes in four dimensional spacetime is studied within the extended phase space. For $m=0$, there are no inversion curves and the whole $P-T$ plane with $M>0$ is the cooling region. While for $m\ne 0$, the properties of the Joule-Thomson expansion are found to be controlled by a combined parameter $k+c_2{m}^2$. When $k+c_2{m}^2>0$, we analytically obtain the inversion curves $\tilde{T}(\tilde{P})$ where the Joule-Thomson coefficients are zero. They separate the $P-T$ plane into the heating region (left side) and cooling region (right side). The position of the heating region and cooling region in $P-T$ plane are in contrast to those of the van der Waals system. The inversion curve contains two branches, one with positive slope and the other with negative slope. This feature is found for the first time in the black hole system and is similar with that of the van der Waals system. When $k+c_2{m}^2=0$, the inversion curve is a straight line, above which is the cooling region and below which is a region with $M<0$. When $k+c_2{m}^2<0$, there are no inversion curves and the whole $P-T$ plane with $M>0$ is the cooling region.