To study the distribution change of acetylcholinesterase(AChE) of Aspidogaster conchicola reproductive organ in different development stages and explore the roles of neurotransmitter Ach in the trematode reproductive activity，Aspidogaster conchicola was collected from the Anodonta and was divided into larval stage groups and adult stage groups according to internal strucutre of the trematode under microscope after maked into living body tabletting. The acetic acid Carmine staining and the histochemical staining were used to display the distribution of AChE in two stages of the trematode and distributional difference of AChE was contrasted. The result displayed the testicles and penis sac of the trematode first appears positive reaction,followed by the vitelline gland, the fallopian tubes and the last paragraph of uterus. And its attached, digestive and excretory organs appear the AChE positive reaction in the early stage and its whole development process. The brain ganglion and ventral nerve trunk is clearly visible at each stage of the trematode and the central nerve structure is the most perfect in the maturing stage. It hint neurotransmitter Ach may participate in the trematode reproductive activity.