Studies on grozvth, node development and estimated yield were conducted on Rotan manau (Calamus manan) planted under stands of rubber (Hevea brasiliensis) atDengkil, Selangor. Survivalin the 8th year was 74.8%. Mean stem length varied with those plants at the lower slope doing very well, (14.21 m) compared with the mean stem length for the whole plot (9.98 m). The relationship between the intemode number (X) and the total stem length and the length of stem that is dried can be obtained using a regression method. A few equations were produced through this method. Studies on the intemode diameter and projected yield were also carried out, but more observations are required for more precise results. Negative effects of rattan were not evident on the rubber trees. In establishing a rattan plantation under rubber, it is advisable that the planting distance be widened. The fronds of rattan need to be cut to allow better passage during tapping.