PURPOSE: To execute the subscriber line test with the operation of a general subscriber by providing a voice responding device and a line testing device to execute the test in accordance with the operation of a subscriber in a subscriber line testing system.

CONSTITUTION: When a special number to execute a subscriber line test is dialed from a telephone set 1, the telephone set 1 is connected to a line testing device 8 by the control of a central processing unit 10. When connection is completed, since the voice to instruct a testing procedure sound-recorded beforehand is sent from a voice responding device 9 to the telephone set 1, a subscriber executes the operation of the telephone set 1 base on the instruction by the voice. The line testing device 8 detects the operation, and executes the function test of the telephone set 1 automatically or the automatic measurement of the characteristic of a subscriber line 2. When one test is completed, the procedure of a next test item is successively informed, the measurement test is executed, and the result is stored into a magnetic disk device 11.