Whenever a mass of soil has an inclined surface, potential always exists for part of the soil mass to slide from higher location to a lower location. Sliding occurs if the shear stresses develop exceedingly over the shear strength of the soil. This phenomenon is very important to observe, especially if in the surrounding of the inclined surface location is block of houses. In January 2000 to February 2001 in some areas of Indonesia disasters had happened,one of them is soil sliding. It happened three times, In Central Java, so the catastrophes can´t be avoided. Based on the problems above. the phenomenon of soil analysis. The first is known as·the Cullman method, it is only applicable to vertical or nearly vertical slopes. The second might be called the stability number method.