Abstract: A local area network control apparatus is interposed between a host computer whose main storage stores an appropriate number of user programs and a plurality of interactive termials which have protocols of any desired level. The apparatus comprises a program module which has a predetermined bypass function, a program module which has a function of executing a specified protocol, and a control table in which names of the user programs to be handled, designations of the interacting terminals thereof and protocol execution ranges thereof are set as parameters for required data transmission/reception. The protocols are selectively executed depending upon the contents of the control table in which the names of the user programs to be handled, the designations of the interacting terminals thereof and the protocol execution ranges thereof are set as the parameters for the required data transmission/reception.