Lightning is a natural phenomenon that occurs because of an ionization process and it can lead to the phenomenon of electron charge jumps from clouds to the surface of the earth or vice versa. In addition, if the electron charge in the cloud gets bigger, then the induction charge is getting bigger too, so the potentials difference between the clouds and the surface of the earth is also getting bigger. Furthermore, the lightning phenomenon will be a threat to high buildings. Therefore, to protect the interference from lightning strikes, each high building is installed with a lightning rod for grounding systems as a safety when lightning strikes occur. It is recommended to increase the need for a protection system against lightning strikes in the library building of Universitas Muhammadiyah Yogyakarta, because that building is in the Special Region of Yogyakarta which has a thunder day of 46 times a year, which means it is quite high. However, the method that can be used to find out the protection system when a lightning strike occurs in the library building of Universitas Muhammadiyah Yogyakarta was by conventional and non-conventional methods. In the conventional method was done by measuring the angle of protection and the diameter of the lightning channel protection against lightning strikes at the library building, and the result was obtained a protection angle of 45 degrees with a diameter of 34 meters. Then in the non-conventional method, it was done by measuring the protection radius and the radius of the lightning channel protection against lightning strikes in the library building of Universitas Muhammadiyah Yogyakarta, and a protection radius of 50 meters has been obtained with an area of protection radius of 7850 m2.