Aiming at the problem of available water conservation in desertification ecological restoration, we prepared the water retention materials with montmorillonite(MMT) modified by Castor Oil Polyoxyethylene Ether(10) (EL-10) emulsifying vegetable waxes. The water retention property was studied in simulated desertification climate, and the materials were analyzed and characterized by UV-Vis, SEM, FTIR and XRD measurements. Moreover, a UV carbon arc lamp was used to test the resistance to aging. The experimental results show that the emulsion has good dispersity. Both the water retention property and the aging resistance performance of the modified clay were excellent. The lamellar structure and chemical composition of MMT had no obvious changes before and after modification. The surfaces of clay particles were coated uniformly with modified MMT, so the loose clay particles were cemented together by vegetable waxes. Meanwhile, the original big hydrophilic pores between the clay particles turned into capillary hydrophobic pores. So the clay particles formed a bonding layer which could inhibit water evaporation. Grass-planting experiment showed that reasonable mass ratio of vegetable waxes and EL-10 was 1:18. The materials not only had great water retention property but also maintained sound air permeability so that the germination rate of grass seed significantly increased from 8% to 52%.