Study was conducted at Cheringa acid sulfate soil of high agricultural potentiality (if they can be reclaimed by appropriate methods), which occurs in the coastal mangrove floodplain area of Cox's Bazar in Bangladesh. The study area is popularly known as tropical monsoon climate, or perhaps more precisely a maritime tropical climate, has three main seasons, namely, the monsoon or rainy season, the dry or winter season and the pre-monsoon or summer season. During this time drying out of the land, depletion of soil moisture and upward translocation of salts through capillary rise of subsoil moisture or ground water take place. The pre-monsoon season extends from March to May and has the highest temperature and evaporation of the year. This is the period when most of the desiccation in the soil occurs accompanied by salinization and oxidation. Once this area was occupied for centuries by dense mangrove forest like sullyakata (Dalbergia spinosa), hargoza (Acanthus ilicifolius), golpatta (Nypa fruticans), gewa (Excoecana agallocha) and keora (Sonneratia apetala) etc. But now, about 90 per cent of the areas have been cleared for cultivation (local farmers have been trying to grow aman rice by fresh water irrigation where it is available) or salt production or shrimp culture. Most of the area have been subjected to tidal flooding with brackish and saline water from the tributaries of Maheskhali and Naf rivers. Sample and analysis of soils: A pit of approximately 1.5m deep was dug depending on the ground water level during March, 1990. The soil profile was studied in accordance with the standard methods. The bulk samples obtained from each horizon were stored in the field-moist condition (by putting the soil samples into polyethylene bag in air-tied box) just prior to laboratory analyses whereupon sub-samples were air-dried and gently crushed to pass a 2mm sieve. After treatment with 1M CH3COONH4. (pH 5.0) and with 30% H2O2 to remove free salts and organic matter, respectively, particle size distribution was determined by the pipette method. Soil moisture at field condition was determined by over-night oven drying at 105oC. Organic matter content was determined by wet combustion with K2Cr2O7. Soil pH was measured in the field using Helling-Truog test - kit and for the air-dried soils in soil-water (1 :1) and soil-1M KCI (1 : 1) suspensions using a Corning pH meter Model-7. The pH was also determined after H2O2 treatment with slight modification of H2O2 concentration. For the saturation extract of soils, the electric conductivity exchangeable sodium percentage and sodium adsorption ratio, water-soluble Na+ and K+(flame photometry), water- soluble SO42-S and CI, and water-soluble CaH, Mg2+, Fe1+, AI1+ MnH and ZnH (atomic absorption spectrornetre) were determined. Exchangeable Na+, K+, Ca2+, Mg2+, Mn2+ and Zn2+ were extracted with 1M CH3COON4, (pH 7.0) and determined by flame photometry (Na+, K+) and atomic absorption spectrometry. Exchangeable AI3+ (1M KCI) and Fe3+ (1M CH3COON4, : pH 4.8) were determined by atomic absorption spectrometry. Total contents of Si, Al, Fe, Ti, Na, K, Ca, Mg, Mn, Zn, S and P were determined by x-ray fluorescence spectrometer (Rigaku Denki KG 4) method. Soil samples were prepared as glass specimens for analyses of P, K, Ca, Mg, Fe, Mn, Si, Al, Ti and mix - pressed samples ofr analyses of S, Zn, Na.