Case-based teaching is a teaching method which is based on real situation and cases , and is in-creasingly concerned in science education field .Cases in science classes can be divided into types such as guiding cases, instant cases, analyzing cases, dilemma cases, phase cases and laboratory cases , which have their corre-sponding teaching strategies .On this basis, the author designed teaching cases and made comment according to the resources from American national case -based teaching center website .The development , usage and sharing of ca-ses in science education are the base of effective application of case -based teaching .In addition , teaching view-points should be changed , appropriate training courses of case -based teaching should be applied to reply the challenge of case-based teaching to science teachers .