Two genus , Allium L. and Stipa L., have different water use strategies to adapt themselves to arid environment. In this Master's thesis, the two species of Allium L. and the two species of Stipa L. were chosed to study the drought-resistant characteristics of two genus .The chosed four species are constructive species in desert steppes , with good representation. The drought-resistant characteristics of two genus were studied through irrigating experiment, to determine the water potential, water co...