Abstract: 4-Alkyl derivatives of 2,6,7-trioxa-1-phosphabicyclo[2.2.2] octanes are extensively used for spectroscopic studies and are candidates for use as flame retardants, vinyl resin stabilizers and antioxidants^[1-4]. Bicyclic phosphates are antagonist of GABA receptor, further research show that these compounds act on the chloride ion channel connecting with GABA receptor. So bicyclic phosphate can act as drugs to probe the Cl^- channel. Our preliminary pharmacological results indicate that these bicyclic phosphorus compounds should be handled with great care because of their high toxicity to mammals. Some derivatives of bicyclic phosphates have been prepared in our laboratory.