The field of clinical laboratory tests is facing an increase in the number of test items as well as a corresponding diversification due to the demands of medical institutions as well as improvements in analytical techniques. To respond to this situation, medical institutions have been promoting systematization of their testing procedures; information exchange among the institutions has likewise expanded with the use of media such as on-line systems and internet. Standardization of interfaces has been proposed to secure a common framework compatible with different types of information. Some embodiments in this country includes; (1) Interface Standards on Clinical Laboratory Information For information exchange, the format and reporting comments used in the media systems were standardized under the sponsorship of The Medical Information System Development Center, with a publication issued on 1993. (2) Standardization of Laboratory Test Code Standardization of codes for information exchange has been established under the sponsorship of The Japan Society of Clinical Pathology (Laboratory Test Coding Committee), through the systematization of laboratory test code used in media systems. A publication entitled "Classification & Coding for Clinical Laboratory Tests (8th edition in 1992, 9th edition in 1994 and supplement in 1996)" has been issued. The system for "Classification & Coding for Clinical Laboratory Tests" is divided into 5 components; (1) analyte code, (2) identification code, (3) specimen code, (4) methodology code, and (5) data classification code. The Laboratory test codes are precisely classified by "(1) analyte code", and then are identified by combination of additional codes such as specimen and methodology codes. In this year, we are making a new easily-used-codes composed of 5 Arabic figures.