This memo defines a protocol for use with relational database systems in a TCP/IP based internet environment. This protocol is intended to make interoperability among different database systems possible. It is built on RPC (Remote Procedure Call) with a client/server type of relationship. This document also defines the concept of Unit of Work. The work of Network Database is involved with Data Conversion, Security, I/O Buffer Management, and Transaction Management. They will be described one by one in this document.