Abstract:By using paraffin method, the root anatomical structure of Philodendron pitfieri Engl. under water culture were observed, and the morphological characteristics adapting to aquatic environment were discussed. The results showed that compared with soil culture, the root cap was not obvious with less amyloplast and polysaccharose substance under water culture. The root epidermis under water culture was thinner than that of soil culture, with little root hair or not, in which cortex parenchyma tissue developed with big cell, solution proliferative aerenchyma in intercellular space, and thin cell wall. However, the root cap under soil culture was big, with strong PAS reaction and no aerenchyma tissue.