The objectives of this investigation were to study the effect of herbicide bispyribac-sodium at rate of 16 g a.i/fed on Oryza sativ (L.) cv. Sakha 104, Echinochloa crus-galli (L.) and Echinochloa colonum (L.) grown under Egyptian ecosystem (Nile delta ecosystem). Morpho-physiological changes were take into account were growth reduction, chlorophyll pigment content reduction and reduction of some anatomical leaf parameters in O. sativa, E. crus-galli and E. colonum treated with tested herbicide. Moreover, increasing in membrane integrity (permeability) and leaf water deficit and reducing in leaf water contents were obtained in all tested plants treated with bispyribac-sodium. Ultrastructural changes in tested plants after bispyribac-sodium foliar application were noticed as cytotoxic features (programmed cell death). Cytotoxic features were take into account were mesophyll cell plasmolysis, irregular, granular nucleus, reduction in thylakoid membranes in treated plants compared with untreated plants. The obtained results will improve our understanding to tested herbicide mode of action, which may be overcome or reduce the side effects on non-target plant (O. sativa).