Abstract. The aim of this work was to analyse structure resistance, capillary rise, mechanical strength and other physical properties in fine textured soil in North Libya. The examination of these characteristics was carried out on laboratory modelled soil aggregates (1 cm³ volume) with special methods developed in the Soil Science Department of the Agricultural University in Poznań.The samples were taken from red soils (Terra Rossa) occurring in the Cyreneica Region. Ali these soils belong to clayey textured group. Investigations have shown surprisingly low resistance to dynamic and static water action for dry aggregates and very high for moist ones. Percentage of  secondary aggregation' is very high, in most cases exceeds 80 % of total soil mass. The secondary microaggregates with diameter of 3-1 mm and 1-0.5 mm predominate. The maximum capillary water capacity of soil aggregate models in 'free swelling' conditions is so high that it is in-comparable to soil porosity.