Abstract: Electron microscopic examination shows that after treated with 0.10 mg·L^-1monocrotophos for 96 hours, the gill cell of Penaeus chinensis has an obvious ultrastructural variation:the parallel, ordered structure of muscle fibres is destroyed,endoplasmic reticulum is swollen up, dilated and vesiculated,and ribosomes on the surface of RED is chipped away in large numbers. In golgi body, the dictyosomes is swollen up,and vesicles is dilated and even broken up. Cristaes in mitochondria is slightly swollen up, and disintegrated partially. Cuticle of gill fibre is denatured and dropped off, and nuclear membrane is swollen up and partially dissolved.

Key words: Monocrotophos, Penaeus chinensis, Ultrastructure, Toxicity effect, urbanization, data envelopment analysis, Beijing-Tianjin-Hebei agglomeration, nitrogen offset, reactive nitrogen