An exhaust gas purification catalyst extending in an exhaust gas flow direction, the exhaust gas purification catalyst comprising: a substrate; first catalyst layers provided in the substrate; and second catalyst layers provided in the substrate; wherein the substrate comprises: inflow-side cells each extending in the exhaust gas flow direction and having an open end on an exhaust gas inflow side thereof and a closed end on an exhaust gas outflow side thereof; outflow-side cells each extending in the exhaust gas flow direction and having a closed end on an exhaust gas inflow side thereof and an open end on an exhaust gas outflow side thereof; and a porous partition wall separating the inflow-side cells and the outflow-side cells from one another, wherein the first catalyst layers each have a portion that is formed on a surface on an inflow-side cell side of the partition wall, and extends from an end on an exhaust gas inflow side of the partition wall along the exhaust gas flow direction, wherein the second catalyst layers each have a portion that is formed on a surface on an outflow-side cell side of the partition wall, and extends from an end on an exhaust gas outflow side of the partition wall along a direction opposite to the exhaust gas flow direction, and wherein the first catalyst layers and the second catalyst layers satisfy the following expressions to: L1 < L2 T 1 < T 2 WC 1 > WC 2 wherein L1 represents a length of the first catalyst layers, L2 represents a length of the second catalyst layers, T1 represents a thickness of the portions of the first catalyst layers, T2 represents a thickness of the portions of the second catalyst layers, WC1 represents a mass of the first catalyst layers per unit volume of a portion of the substrate provided with the first catalyst layers, and WC2 represents a mass of the second catalyst layers per unit volume of a portion of the substrate provided with the second catalyst layers. a substrate; first catalyst layers provided in the substrate; and second catalyst layers provided in the substrate; wherein the substrate comprises: inflow-side cells each extending in the exhaust gas flow direction and having an open end on an exhaust gas inflow side thereof and a closed end on an exhaust gas outflow side thereof; outflow-side cells each extending in the exhaust gas flow direction and having a closed end on an exhaust gas inflow side thereof and an open end on an exhaust gas outflow side thereof; and a porous partition wall separating the inflow-side cells and the outflow-side cells from one another, wherein the first catalyst layers each have a portion that is formed on a surface on an inflow-side cell side of the partition wall, and extends from an end on an exhaust gas inflow side of the partition wall along the exhaust gas flow direction, wherein the second catalyst layers each have a portion that is formed on a surface on an outflow-side cell side of the partition wall, and extends from an end on an exhaust gas outflow side of the partition wall along a direction opposite to the exhaust gas flow direction, and wherein the first catalyst layers and the second catalyst layers satisfy the following expressions to: L1 < L2 T 1 < T 2 WC 1 > WC 2 inflow-side cells each extending in the exhaust gas flow direction and having an open end on an exhaust gas inflow side thereof and a closed end on an exhaust gas outflow side thereof; outflow-side cells each extending in the exhaust gas flow direction and having a closed end on an exhaust gas inflow side thereof and an open end on an exhaust gas outflow side thereof; and a porous partition wall separating the inflow-side cells and the outflow-side cells from one another, wherein the first catalyst layers each have a portion that is formed on a surface on an inflow-side cell side of the partition wall, and extends from an end on an exhaust gas inflow side of the partition wall along the exhaust gas flow direction, wherein the second catalyst layers each have a portion that is formed on a surface on an outflow-side cell side of the partition wall, and extends from an end on an exhaust gas outflow side of the partition wall along a direction opposite to the exhaust gas flow direction, and wherein the first catalyst layers and the second catalyst layers satisfy the following expressions to: L1 < L2 T 1 < T 2 WC 1 > WC 2 wherein L1 represents a length of the first catalyst layers, L2 represents a length of the second catalyst layers, T1 represents a thickness of the portions of the first catalyst layers, T2 represents a thickness of the portions of the second catalyst layers, WC1 represents a mass of the first catalyst layers per unit volume of a portion of the substrate provided with the first catalyst layers, and WC2 represents a mass of the second catalyst layers per unit volume of a portion of the substrate provided with the second catalyst layers.