According to the one embodiment, a memory system includes a semiconductor memory device and a memory controller. The semiconductor memory device includes: first and second memory cells stacked above a substrate; a first word line coupled to the first and second memory cells; a first bit line coupled to the first memory cell; and a second bit line coupled to the second memory cell. A first state read operation includes a first read operation for reading data from the first memory cell and a second read operation for reading data from the second memory cell. A first read voltage is applied to the first word line during a first period for executing the first read operation, and a second read voltage is applied to the first word line during a second period for executing the second read operation.