Experiments of nucleate pool boiling were carried out on three kinds of heating surfaces and five kinds of liquid in the range of liquid level from 1mm to 30mm. As a result, the following facts were disclosed. It was found invariably in each liquid that coefficient of boiling heat transfer remains nearly constant at the liquid level higher than that which is inherent in each liquid and that it increases as the liquid level becomes lower than that value. The slope of boiling characteristic curve in such a low liquid level is different from that of usual liquid level. The effect of liquid level on boiling heat transfer coefficient depends on the liquid properties and heat flux and becomes more conspicuous as heat flux decreases. According to the dimensional analysis based on the facts mentioned above, coefficient of heat transfer was succesfully correlated.