Bangladesh is a tropical country and receives heavy rainfall during the rainy season. The average rainfall in the coastal region is more than 3000 mm, against an average rainfall of about 2400 mm in Bangladesh. In the coastal district, high salinity in surface and ground water and rainwater harvesting for drinking purposes is a common practice in a limited scale for a long time. In the present context of arsenic pollution of shallow ground water aquifer, rainwater harvesting is being seriously considered as an alternative option for water supply in the arsenic affected areas. There is no extensive study of the seasonal variation of harvested rainwater as well as its suitability for drinking purpose throughout the year especially during the dry period. The main objectives of this book are to investigate seasonal quality of harvested rainwater, mineral contents and people's perception of rainwater harvesting. This study was performed at Shyamnagar thana under Satkhira district, one of the coastal area of Bangladesh. Water sample was collected from nine different storages of rainwater harvesting system for field and laboratory test of the water quality parameters.