Abstract: There are five genera of Nymphaeaceae in China:Nelumbo, Brasenia, Euryole, Nymphaea and Nuphar. Pollen morphology of 2 varieties, 11 species representing 5 genera was examined under light microscope and scanning electron microscope. The structure of exine of Nymphaea alba and Nelumbo nucifera was also examined under transmision electron microscope. According to the type of aperture, it may be divided into three types:(1) Anasulcate type, Brasenia, Euryale and Nuphar. Pollen grains long ellipsoidal and ellipsoidal in polar view, and boat-shaped in equatorial view. Ornamentation of exine granulate in Byesenia, spinulate in Euryale and long spinate in Nuphar. (2) Zonasulculate type:Nymphaea. It may be subdivided into anazonasculate and zonizonasculate type. Pollen grains circular in polar view, and circular or subcircular in equatorial view. Ornamentation of exine tuberculate, granulate or spinulate. (3) Tricolpate type:Nelumbo. Pollen grains subcircular in polar view, and subcircular or ellipsoidal in equatorial view. Ornamentation of exine rough granulate under light microscope, but rugulate under scanning electron micro-scope. The structure of exine Nymphea alba and Nelumbo nucifera were examined under transmision electron microscope. The former has a granular structure with more or less homogeneous granules, but the latter a collumellar structure. According to the idea about the evolution of pollen grains in primitive Angiosperms proposed by Walker, the type of granular structure is a primitive type, and that of collumellar structure a advenced one. A number of taxonomists have considered that Nymphaeaceae is a primitive and heterogeneous family. On the basis of the pollen morphology of this family, it may be supported for this view-point. The evolutionary relationships among the pollen grains in this family was also discussed.