Golgi vesicles (GVs) are closely involved in pollen tube growth. In the present study, we investigated the role of GV proteins, the main component of the isolated GVs, in germinating pollen. A GV-specific protein (GVP) was isolated by two-dimensional IEF-SDS-PAGE from a GV preparation extracted from Camellia japonica pollen. The isolated GVP had an apparent molecular mass of 70kDa and an isoelectric point of pI 5.2. The localization of GVP was investigated immunochemically using a mouse antiserum against GVP. The antibody reacted with the cytoplasm, and also with the new wall layer inside the intine, in the grain region of the germinating pollen, but not with the wall of the mature quiescent pollen grain. In germinating pollen, the antibody reacted with the inner callosic layer of the pollen tube wall, the GVs in the cytoplasm, and the callose plug. Similar results were also obtained from Camellia sasanquca, C. sinensis and Lilium longiflorum pollen. Therefore, it seems that GVP occurs in the callose-rich regions of the pollen wall, as well as in GVs; suggesting a relationship between GVP and callosic wall formation.