Two newly naturalized plants are reported in this paper. Cecropia peltata L. (Cecropiaceae) and Tabernaemontana elegans Stapf. (Apocynaceae) have been naturalized in low elevation mountain of Jushan area of Nantou city in central Taiwan. They are introduced and cultivated at botanical garden plant of Taiwan. Description, line drawing, photographs and a distribution map of those two species are provided.