四川省除西北隅一小部属黄河流域外,全部属于长江流域。长江全流域之面积为一二八万平方公里,而本省面积四○万,约当全部之三一%。长江重要支流十一,而在川境者有四,即岷江,沱江,嘉陵江及黔江是也。适与四川之省名相合。一、川江之分布川省地形,为一完全之盆状。四周崇山环绕,中部低下平坦。地质上乃古代一内陆湖盆,至中生代之末叶,盆水已乾枯无余,故今日全省河川皆取顺向河谷,求心的流向盆地之底。

Of the total area of the Yangtze Basin (1,280,000 square km.), 400,000 sq. km.or one third lies in Szechwan.The river also receives within the province four of itseleven main tributaries: the Min, the Tou, the Kialing and the Ch'ien.