a client card mail system , comprising : means for storing client information including individual information of clients &# 39 ; code number , name , sex distinction , age , address and telephone number ; means for storing information of the goods for sales company for the sales goods , departments , classes of the goods name , goods codes , prime unit prices , and sales unit prices ; means for storing information of the goods purchased by the clients ; and means for retrieving clients &# 39 ; information of the clients who actually purchased the goods setting the conditions of periods and goods classes from the information of the goods purchased ; and means for outputting and printing the results retrieved . according to the present invention , the clients &# 39 ; taste and living custom can be grasped to enable propaganda activity without waste , and there is provided a client card mail system making use of a method for storage and retrieval of fractionalized data .