Abstract: By means of scanning electron microscope (SEM) and resin casting method, the morphological structure of the vessel element in plants of Aceraceae in Heilongjiang province which includes 8 species in Acer Linn. is studied, The result shows that the length of vessel element is between 187.5 μm and 133.00 μm, except for Acer mandshurica Maxim. which has large longer length than other species. The width of vessel element is between 17.06 μm and 28.00 μm. In the types of pits of vessel element, there are alternate pitting only, opposite pitting only and both. The pits between vessels are distributed in groups, most of them show some forms. The relationship between the main characters of vessel element and their habitat is studied.

Key words: Aceraceae, vessel element, SEM