To better predict and evaluate responses of tree growth and forest productivity to the changes of precipitation pattern and seasonal drought under global climate change scenarios, throughfall reduction experiments including 50% of throughfall and natural rainfall (control) treatments were conducted in Castanopsis hystrix and Pinus massoniana plantations of warm subtropical region over a three-year period (2015-2017) . Diameter at breast height (DBH) ,litterfall production and leaf area index of both plantations were investigated,respectively. The results showed that throughfall reduction resulted in a 31.8% decrease of annual increment of DBH of C. hystrix in 2017 and had no significant impact on that of P. massoniana. Leaf area index under throughfall reduction decreased by 8.8% in C. hystrix plantation and decreased by 7.2% or remained unchanged in P. massoniana plantation. Branch litterfall in 2015 and total litterfall in 2017 of C. hystrix increased by 29.6% and 35.8% by throughfall reduction,but leaf litterfall of other tree species (except for P. massoniana) in P. massoniana plantation declined by 50.7% in 2015,with no significant difference for other litterfall components. In conclusion,throughfall reduction had consequences of drought stress in both C. hystrix and P. massoniana plantations,with inter-annual variation and inter-specific differences.