Terrestrial snail, Monacha cantiana was used as a bioindicative organisms to assess the ecotoxicological effect in El Behira governorate. Five districts (El-Dalengat, Kom Hamada, Damanhour, Shoubrakhet and Etay El-Baroud) were selected for the animals collection during winter and spring seasons of 2008/2009. AChE activity was observed at a highest value (71.65 mmole/mg protein/min) in Damanhour district which considered a control zone. Lactic dehydrogenase (LDH) is an indicative criteria of exposure to chemical stress, was showed the lowest inhibition (13.7 IU/ mg protein) in Etay El-Baroud. On the other hand, from the family of enzymes with important roles in the biotransformation of xenobiotics substances, glutathione-S-transferase (GST) was chosen.  It recorded significantly decreasing in activity of snails collected from El-Dalengat, Damanhour and Etay El-Baroud districts, respectively, with values (63.01, 73.54, and 87.99%) compared with control. The terrestrial snail was an efficient bioindicator that accumulate bioavailable contaminants as a diagnosis tools for toxicological responses.