Abstract: Due to memristor's unique electrical characteristics, it has a good prospect in resistive random access memory, artificial neural networks and circuits. The cross -bar was widely used in two -dimensional integration, the three -dimensional integration can be divided into stacked cross -bar array and vertical cross -bar array. The two kinds of three -dimensional structures, models under different mechanisms, window functions and circuit structure were compared and discussed, the method of improving the integration density was analyzed. The memristor's biological synaptic behaviors, application in artificial neural networks and circuits were also introduced.

Key words: memristor, resistive switching, cross-bar, artificial neural network, synapsis