We have developed a new ice valve to close or open liquid flow in a mini/micro channel. Unlike the traditionally used valve, no moving elements are needed in this normally open system. By freezing the working fluid running inside the channel using a thermoelectric cooling device (TECD), the flow can be blocked due to ice formation. If switching the TECD to heating, the frozen liquid becomes thawed and flow in the channel resumes its running state again. Several experiments were carried out to characterize the working performance of the ice valve for a micro tube. A theoretical model was established to analyze the time response constant of the ice valve. Without any leakage, being very clean, and easily controllable through electricity, this ice valve may find significant applications in microfluidics or nanofluidics.