Paddy, tea, rubber and coconut termed as principal agricultural crops contribute substantial percentage of GDP for agricultural sector. percentg a self sufficiency ratio above ncipal agricultural crops in Sri Lanka which contributes higher proportion to the agrSubsisySubsistenseThe objectives of this study are to find the trend of percentage share of agriculture sector to GDP and share of principal agricultural crops to Agricultural GDP from 1956 to 2016 and study the production and the land extent of principal agricultural crops over the period. The study uses the secondary data which was gathered from Central Bank of Sri Lanka Annual Reports and Department of Census and Statistics. The data was initially tabulated and after that graphs were produced and based on the detected patterns certain inferences were made. The proportion share of GDP of agriculture sector was nearly 45% in 1950 and touched 7% in 2016 where it showed a diminishing trend. Similarly, contribution of principal crops also displayed a decreasing contribution. The percentage portion of percentage share contribution of all four principal agricultural crops presented a lessening trend whereas paddy decreased significantly. The production of tea and area under cultivation continued at a certain level since 2006 and detected a considerable decline in 2016 as a result of supply and demand factors together. Production of rubber showed a rising trend from 2006 and reached its peak in 2012 and thereafter it declined significantly in each year. The production of coconut and extent of cultivation remained at the same level with regular fluctuation. Principal agricultural crops become an unpleasant venture for farmers related to other field crops.