Some geotechnical problems such as foundation support capacity failure and slope sliding occur on mudrock soils. Uniquely, mudrocks have excellent durability levels under natural hoarded conditions. However, under open and exposed atmospheric and hydrosphere conditions, mudrocks are much weathered, degraded and their durability decreases dramatically. Slake endurance testing was performed to determine the level of resistance of mudrock to weathering factors. The mudrock resistance level is expressed in the Slake Endurance Index (Id). Efforts to improve mudrock durability are done by adding semen as a stabilizing agent. The experimental results showed that the cement had an effect on the durability of the sludge during the wetting and drying cycle. The value of Id in the 5th cycle for mudrock by mentioning the cement shows the number 61.37%. Number of difference of about 61,12% with the value of Id cycle 5 mudrock without cement showing the number 0,25%.