This paper presents a kind of water-saving material of the fly ash composite growth substrate in order to solve the problem of the lawns high water consumption. The morphology of the growth substrate was observed by scanning electron microscope. The water keeping and releasing characteristics of the growth substrate were analyzed by the fast moisture analysis and thermal analysis, respectively from the macro and micro perspective. Compared with the common cultivated soil planting tests, the differences between the composite growth-substrate planting and the common planting were got under the similar culture environment. The results show that the typical micro-morphology of the growth substrate is the fiber interspersed among the fly ash particles/cluster which is wrapped by the super absorbent resin, and the whole structure has a good performance at water retention and water releasing. The seeds that planted in the growth substrate can germinate and survive basically and the tests preliminary reach the target of the artificial water-saving.