HPMC with low viscosity is widely used in self-leveling. Self-leveling is a very advanced construction technique. Since the whole ground is naturally leveled with very little interference of construction personnel, flatness and construction speed are greatly enhanced compared with the previous manual smoothing processes. In self-leveling, the dry-mixing time uses the excellent water-holding capacity of Hydroxypropyl Methylcellulose. Since self-leveling requires the well stirred mortar automatically leveling on the ground, the use of water materials is relatively large. Adding Hydroxypropyl Methylcellulose will control the water-holding capacity of ground surface after pouring, bleed less obviously, lead to high strength of the ground after drying and small shrinkage, and thus greatly reduce cracks. Moreover, the addition of Hydroxypropyl Methylcellulose can also provide with viscosity, function as the anti-settling additive, enhance mobility as well as pumpability, improve the efficiency of flooring.