In this study, we isolated and characterized GMSCs in 2D and 3D culture conditions and found that GMSCs in 2D and 3D infusion can significantly ameliorate the IMQ-induced murine psoriasis-like skin inflammation, reduce the levels of Th1- and Th17-related cytokines IFN-γ, TNF-α, IL-6, IL-17A, IL-17F, IL-21, and IL-22, and upregulate the percentage of spleen CD25+CD3+ T cells while downregulate the percentage of spleen IL-17+CD3+ T cells. This evidence concerns the gene IL21 and psoriasis.