Cytological changes in rice Oriza sativa (L.) cv. Sakha 104, and two different rice weeds i.e. Echinochloa colonum (L.) and Echinochoa crus-galli (L.) after foliar application with fenoxaprop-P-ethyl at rate of 26.25 g a.i /fed. and penoxsulamat rate of 10 g a.i/fed. were investigated. Mesophyll cell plasmolysis and unevenly thickened cell walls were showed in O. sativa after foliar application with fenoxaprop-P-ethyl. Mitochondria multi- fission and increasing in mitochondria number per cell were found in rice and E. crus-galli mesophyll cells. Thylakoid membrane reduction and plastoglubule were noticed in chloroplast of mesophyll cells in E. colonum were recorded. Furthermore, re-growth of E. crus-galli and E. colonum occurred after foliar application with fenoxaprop-P-ethyl. These findings will improve our understanding for the tested herbicides mode of action in wanted and unwanted plants at ultrastructural levels.