During the germination of coconut seed, a haustorium was formed from the distal portion of the embryo. Compared with various parts of tissues within a haustorium, the surface tissues were markedly different in (1) bearing undulating structure which closely attached with the degradating endosperm, (2) possessing starch grains and oil droplets in developing haustorium, (3) accumulating relatively high amounts of sucrose and starch, and (4) being the presence of considerably higher activities of phosphoglucomutase and phosphoglucose isomerase. In addition, vascular bundles were situated near the outer surface. In view of this tissue specific features, it is likely that the surface layer consisting of epithelium and adjacent cells plays a key role in absorption of oil reserves released from degraded endosperm and conversion into sugars. Possible interactions between haustorium and endosperm are discussed.