Abstract: Using bagasse as biological template, the hierarchical porous structure ZnO was prepared by morphgenetic transformation method. The ZnO samples were phaseanalyzed by Xray diffraction (XRD), scanning electron microscopy (SEM) and specific surface area test method, and the gassensing experiment was carried out. The results show that the samples obtained after calcination is pure wurtzite hexagonal ZnO with bagasse template completely removed. The surface of ZnO samples show honeycomblike structure, which is formed by the interconnection of porous channels. The response of hierarchical porous ZnO reaches a maximum of 24.5 at 340 ℃ for 100 cm3/m3 acetone, about 2.23 times higher than that of
 conventional templatefree ZnO. Response time and recovery time are 6 s and 1 s, respectively, shorter  than that of the conventional templatefree ZnO, and it has good gas selectivity.

Key words: bagasse, morphgenetic transformation, zinc oxide, gas sensitivity