This paper proposes a field test method to evaluate the performance of air-conditioning cool storage systems. In this method, the storage capacity, storage efficiency and cooling capacity under actual application conditions are tested and evaluated. This method has three characteristics. Firstly , it is a relatively simple test. Secondly, the performance is measured under the conditions of actual applications. Lastly, the basic functions of energy transfer are measured, and therefore , applicable to different ice storage systems. The applications and benefits of such a test method are discussed . This paper describes the items of testing, Instrumentation, measurements, an uncertainty analysis and the some results of six field tests.