Bacterium have evolved a large variety of stunning morphologies controlled at the microor even nanoscopic level such as cocci, bacillus, vibrios and spirillum acting as templates can lead to the formation of corresponding hollow inorganic replicas. Here, cocci Streptococcus thermophilus has been used as a natural biotemplate to synthesize ZnO hollow spheres via a simple hydrothermal method, followed by calcination. The as-obtained products are characterized by techniques of TG, XRD, FESEM, TEM and N2 adsorption. A possible formation mechanism is proposed which has an effect on the bimodal pore structure of the products with pores in the mesoporous range. It has introduced a new concept to synthesize porous hollow spheres by using bacteria as a biotemplate and has opened up a new pathway to synthesize hollow nanospheres, nanotubes and other kinds of 3D hollow nanostructures with bacteria of different morphologies, dimensionalities and sizes as templates.