A nonvolatile memory and a method of driving the same are provided, which adopt an improved write verify operation. The method of driving a nonvolatile memory device having variable resistance memory cells, bit lines coupled to the variable resistance memory cells, and column selection transistors coupled between the variable resistance memory cells and the bit lines to receive a first control voltage being applied to their gates, includes making the first control voltage at a first level, and changing a resistance of the variable resistance memory cells by providing a write bias to the variable resistance cells; verifying and reading whether the changed resistance enters into a specified resistance window; and changing the first control voltage to a second level that is different from the first level, and changing the resistance of the variable resistance memory cells by providing the write bias to the variable resistance memory cells.