This paper deals mainly with the physico-chemical properties and mineral compositions of red earths, lateritic red earths and latosols developed from basalts under different conditions of biological climate. The content of iron oxide in clays from all soils was higher, being 16.98±0.83%. The iron oxides in clay fraction were dominated by hematites and geothites, but those in coarse fraction by magnetites, hemames and anatases. The free degrees(free Fe₂O₃/total Fe₂O₃) of iron oxides of red earths, lateritic red earths and latosols were 53.3±2.2%. 71.1±2.8%, and 82.8±3.1% respecaively, and silica-alumina ration 3.29±0.05, 2.33±0.05, and 1.89±0.03 respectively. The degree of allitic enrichment strengthened with increase of remperature and rainfall. The weathering leached coefficient ba (ba=K₂O+Na₂O-CaO+MgO molecular ration) was used to indicate the weathering intensity of soils. The ba valus of red earths. lateritic red earths and latosols were 0.22±0.01, 0.13±0.002, and 0.05±0.01 respectively.