This paper describes basic researches on learning contexts of “water” in chemical education. First, the features of “water” as teaching materials were discussed. Second, some previous efforts for the context-based learning of “water” in foreign and domestic cases were summarized. And third, two examples for the learning contexts of “water” were proposed on the basis of some lesson practices.本研究の一部は,平成25~27年度科学研究費補助金基盤研究C(課題番号:25350203,研究代表者:網本貴一)および平成25~28年度科学研究費補助金基盤研究A(課題番号:25242015,研究代表者:古賀信吉)の助成を受けて行ったものである