Two newly naturalized herb species are reported in this paper. Fumaria parviflora Lam. (Papaveraceae) was found in an agriculture area of central Taiwan. Nelsonia canescens (Lam.) Spreng. (Acanthaceae) now well established and naturalized in central and southern Taiwan is an alien plant and a newly recorded naturalized genus in Taiwan. This report gives morphological characters, line drawings, distribution maps, and photographs to aid in their identification.