To check the large area preserved by soil and water conservation measure is the bases to analyse and calculatethe benefits reducingrunoff and sediment by the measure. This paper has checked the true areas preserved byfourcontrol measures of terraces

flatland.forest.grass land in both 14 counties ofwest Shanxi praince and 8 counties ofeast Gansu province on the hilly and gully areil of loess plateau in the middle reaches of the Yellow River by use ofthe results of detailed land survey. The prexervation rata of each control measures has been obtained in broad regionin the above two types of area. The rate has been checked by the result of typical investigation in west Shanxiprovince.A realible basic data has been set for the study of benefits to reduce runoff and sediment by the controlrneasures in the middle reaches of the Yellow River.