Abstract: A method for measuring line parameters of subscriber lines of a telecommunication system in which end devices, exhibiting a capacitance, are connected to two wires of the subscriber lines is disclosed. The line parameters measured include the capacitances between each of the line wires and ground, the capacitance between the line wires, the leakage resistances between each of the line wires and ground, and the insulating resistance between the line wires. This task is accomplished by performing the following steps while the end device is connected to the subscriber lines. These steps are performed in three measuring configurations sequentially: first one of the two wires of the subscriber line is grounded and the measurement is performed in connection with the other, then the other one of the two wires is grounded and the measurement is performed in connection with the first, and then both wires of the subscriber line are connected together and the measurement is performed on the pair.