A field experiment was conducted to determine the effect of different levels of nitrogen (N) on N uptake, yield components, and dry matter yield of japonica (Hatsuboshi) and indica (IR-13) rice varieties. Results showed an increasing trend in the N uptake, rice yield, panicle number, tiller number, and dry matter production, with increased amount of applied N fertilizer. The yield (brown rice) of the two varieties (Hatsuboshi, 3.2 - 6.5 tons ha^-1; IR-13, 2.6 - 6.4 tons ha^-1) did not differ significantly (p°Ü0.05). However, the agronomic efficiency of IR-13 was significantly higher than Hatsuboshi. There was a 30 kg ha-1 increase in the yield of brown rice and about 1.4% increase in the total N uptake for every additional kilogram of applied N ha^-1. Higher correlations (p°Ü0.001) were found between the yield (r = 0.96**; r = 0.99**), number of panicles (r = 0.98**; r = 0.96**) and number of tillers (r = 0.95**; r = 0.98**) and N uptake (r = 0.97**; r = 0.95**) of japonica and indica rice varieties and applied nitrogen, respectively. The increase in yield (ton ha-1) of japonica (y = 1.07x + 2.5) and indica (y = 1.24x + 1.5) could be attributed to the increase in N uptake with increased application of nitrogen and mineralized soil N after flooding. However, best timing and amount of N application should be determined to reduce N losses and increase soil and fertilizer N efficiency while cost of production is also reduced but yield is increased.