The out-of-step protection function is one of the key functions in generator protection. This function detects the loss of generator synchronism, and when such a fault occurs, it is necessary to disconnect the generator from the rest of the system as soon as possible in order to avoid major damages.The algorithms used in the out-of-step protection functions are based on the measurements of generator impedances and they use the impedance vectors to check if all stability criterions are met. This paper describes a new approach to realizing the out-of-step generator protection function by using the direct load angle measurement. The idea behind applying the real time load angle measurement is to faster detect the loss of synchronism.