Abstract: Net photosynthesis rate (Pn) of 1-2 years old Salacca zalacca saplings was measured with CIRAS-2 portable photosynthesis system. The results showed that the first top leaf had the lowest Pn value, while the second leaf to the top had a highest Pn value for both 1yr and 2yr S. zalacca saplings. The Pn value decreased gradually from the second leaf to the top toward to the lowest one. The value of saturation PAR and compensation PAR of the second leaf to the top of 1yr old sapling was 1 500 μmol/(m2·s） and 50 μmol/(m2·s） respectively. There were two peaks in the diurnal Pn variation curve during the day time, which occurred at 10 am in the morning and at 2 pm or 4 pm in the afternoon.