Disclosed is a 3D architecture of ternary content-addressable memory (TCAM), comprising a first transistor layer, a second transistor layer, a third transistor layer and a fourth transistor layer. The first transistor layer and the second transistor layer are disposed on a first plane. The third transistor layer and the fourth transistor layer are respectively stacked on the first transistor layer and the second transistor layer in a second direction perpendicular to the first plane. Two of the first transistor layer, the second transistor layer, the third transistor layer and the fourth transistor layer are a first transistor and a second transistor of a first memory cell of the TCAM. The other two of the first transistor layer, the second transistor layer, the third transistor layer and the fourth transistor layer are a first transistor and a second transistor of a second memory cell of the TCAM.