Abstract: The morphogenesis, structure and hpysiological function of the polysaccharidewall-precursor bodies during pollen generation and pollen tube growth ofLiriodendron chinense and L. tulipifera on alien stigma and stylar were observedand described. 1. Polysaccharide wall-precursor bodies have three shapes:polysaccharide particles, coated vesicles and vesicles;2. Polysaccharide particlesbegan generating during mono-nucleus pollen stage, and reached its peak duringpollen tube extending stage. Polysaccharide wall-precursor bodies were formedthrougth disintegration of starch plasts, protein bodies and lipid drops undercontinual cooperation of dictyosome, endoplasm reticulum and mitochondrium. 3.The shapes of polysaccharide particles changed along with their developmentalstage. During early stage they gathered into a group, and the vesicles in it at firstaPPeared as electron transparent vesicles, then became polyhedral bound byProtein, no-coated polysaccharide particles or coated polysaccharide particles tviththorns conjoined micro-grain or micro-fibril in the late stage;4. The polysaccharide particles moved into the tip of tube, then the fused or free polysaccharideParticles through passed conical ER and fused with the wall in the extendingregion. at last contributed their precursor materials. Some of the coated vesiclesand vesicle groups moved into the tube secondary tip, and were released out ofplasma membrane, then were fused with the inner wall pollen tube and contributedtheir precursor mat6rials. Others moved into tube tip. and contributed theirmembrane fragment in the extending region of wall. Final, the relationship bet\veenincompatiblility and ultrastructure was discussed.

Key words: Liriodendron L, Polysaccharide wall-precursor body, Pollen tub