Abstract
The existing test methods for measuring foaming and antifoaming properties of liquids are reviewed. The foaminess of liquids strongly depends on the test method. A number of methods cover most aspects of foam formation and stabilization. According to the principal of the foam generation, the foaming methods have been classified into two groups ; static and dynamic. The foam stability are expressed in terms of defined parameter such as the lifetime of bubbles, bubble size distribution and the gradual transformation of foam film caused by drainage.