The yeast as microbial foaming agent was introduced into the composites of polyvinyl alcohol (PVA)/hydroxyethyl cellulose (HEC). The PVA/HEC porous composites were prepared by freeze/thaw process. The porosity, water absorption and water retention property of PVA/HEC porous composites were tested in different experimental conditions. The microstructure of the samples was characterized by FTIR and SEM. The thermal stability, crystallinity and mechanical properties of the samples were analyzed by thermal gravimetric analyzer (TG), XRD ray diffraction (X) and universal tensile testing machine, respectively. The results show that the pore of PVA/HEC porous composites foamed by yeast exhibit an elliptical open-cell structure that large cells are surrounded by small cells .It has fast water absorption response rate and good water retention. Its water retention rate fell to the lowest after 24h. Comparing with the PVA/HEC porous composites without yeast foamed, the PVA/HEC porous composites foamed by yeast, its properties thermal stability and mechanical properties are improved. The compression strength and the ultimate compressive stress is 13.2 MPa and 6.4Mpa, respectively.