After the elucidation of the threedimensional structure of Torpedo acetylcholinesterase by X-ray diffraction in 1991,studies by computer modelling and site-directed mutagenesis have led to significant progress in the elucidation of the structure-function relationship of this enzyme. And based upon this,efforts have been made to invcstigale further mechanism of inhibition by irreversible inhibilors (organophosphate), and that of the reactivation of the irreversiblly inhibited enzyme. In addition, progress in study of aging nirchanism of the inhibited enzyme was also reviewed.