A series of samples with same dry density and different moisture contents for comparative tests were made from Malan loess collected from north of Shaanxi province in China. Soil-water characteristic curve of the sample was tested by volumetric pressure plate instrument. By disintegration tests of samples with different initial matric suctions with self-made disintegration device; relation curve of average disintegrating velocity and initial matric suction was gotten. The results of tests indicate that the water stability of dry loess is worse than wet one. There was a logarithmic relationship between average disintegrating velocity and initial matric suction. Influence of matric suction on disintegration of unsaturated remolded loess can be concluded as following two aspects: 1

infiltration speed of water increase by matric suction. Quick infiltration of water increases the pore water pressure

dissolves cement of particles

and cause the softening of loess; 2

during the quick filling of pores in samples

the air of sample come out in the form of bubbles and cause outward pressure.