This paper deals with the relation between loam behaviour and its differential settlements. Experimental results obtained from the foundation soil of a phosphtic fertilizer plant show that factors influencing differential settlements are: (1) Comparatively large compressibility of foundation soil; (2) Anisotropic strength of foundation soil; (3) Overloading and repeat loading effects; (4) Fluctuation of underground water table; (5) Rheologic property of foundation soil.