nowadays, the development of anti cancer drugs is an important subject in pharmacology. bisphosphonates (b.p) are a great choice for design and production of the types of drugs which not only could perform as anti cancer agents but also could inhibit the function of acetyl cholinesterase (ache). ache hydrolyzes the acetylcholine (which is a neurotransmitter in nervous system) using the oh in its serine and blocks its normal activity in central and peripheral nervous system. it has been proven that molecular structure of b.p plays an important role in inhibition of this enzyme. so to illustrate, two new phosphor derivatives 4-ethyl pyridine (a) and 2-ethyl pyridine (b) were designed and synthesized and their inhibiting potential for ache were investigated and observed. both a and b were proven to be similarly reactive and could perfectly decrease the invitro activity of ache. therefore these two products were considered as an effective pre-drug for nervous system deficiencies. the molecular structure of the new synthesized products where identified by spectroscopic methods.