General feature of the Manjil earthquake of June 21, 1990 in Iran and its effects on the ground damage are described putting emphasis on the liquefaction of sand deposits and landsliding which occurred in natural slopes. The liquefaction developed on the fluvial plain in the lower reaches of the Sefidrud river is shown to have exhibited several features in common with those ever encountered in other areas under similar conditions. The landslides which occurred in the mountain flanks in the epicentral area seem to have addressed some new features on the triggering mechanism of the slide intrinsic to earthquake environments.