An automatic digital variable resistor capable of preventing failure in a liquid crystal display panel and an LCD having the same are provided. The automatic digital variable resistor comprises a programmable memory in which an intermediate value of n-bit data is stored, wherein (n≧2) and a voltage adjuster adjusting the intermediate value stored in the memory in response to an external control signal and outputting an analog voltage value corresponding to the adjusted intermediate value, wherein the voltage adjuster further outputs an analog voltage value corresponding to the intermediate value read from the memory when the intermediate value is a maximum or minimum value of n-bit data.