Provided are a weight matrix circuit and a weight matrix input circuit. The weight matrix circuit includes a memory array including n input lines, m output lines, and n×m resistive memory devices each connected to the n input lines and the m output lines and each having a non-linear current-voltage characteristic, an input circuit connected to each of the input lines, and an output circuit connected to each of the output lines. The input circuit is connected to the resistive memory devices such that the weight matrix circuit has a linear current-voltage characteristic.