The purpose of this study was to assess double cut alternate latex harvesting system (DCA) over a 15-years tapping period on clone RRIM600. This experiment was set up in Chachoengsao Rubber Research Center since 1999. Experimental design was a RCB comprising 4 replications with 6 treatments: A; S/2 d2, B; S/3 d2 ET2.5% 4/y, C to E; S/2 d3 ET2.5% 4, 6 and 8/y and F; DCA ((2xS/2 d2 (t,t)). Yields in g/t/t of S/2 d3 ET2.5%, 4-8/y were the highest with more 36-44% of the control S/2 d2. But yield in term of kg/tree/year and kg/ha/year were lower than the others tapping system. Over a period of 15 years, compared to a single cut tapping system (S/2 d2) of equivalent intensity, DCA increased cumulative rubber production by 9%. DCA, S/2 d2 and S/3 d2 ET2.5% 4/y also resulted in higher TPD rates than S/2 d3 ET2.5% 4, 6 and 8/y.