The nitrogen efficiency is very low for rice plant under irrigated ecosystem, might be due to increasing of nitrogen losses through different ways. To increase N efficiency by using slow release nitrogen fertilizer, two field experiments were carried out at the Farm of Rice Research and Training Center (RRTC), Sakha , Kafer-El-Sheik, Egypt, during the two successive seasons of 2008 and 2009 to study the response of Sakha 106 rice variety to different levels of slow release N-fertilizer (Enciabien ) i.e. 0.30,40,50 and 60 kg N/fed compared with 60 kgN /fed as urea form . The obtained results revealed that the application of 60 Kg N/ fed as urea or Enciabien gave the tallest plant, while the same rates as urea produced more tillers and dry matter content. Moreover, there was any significant among all the N-treatments in leaf area index (LAI). As for yield and its attributes, adding nitrogen at the rates of 50 and 60 kg N/fed as Enciabien or 60 kg N/fed as urea gave the highest number of panicles/hill, while number of filled grains /panicle was responded to 40 kg N / fed without any significant difference with 50 and 60 kg N/fed as urea or Enciabien and unfilled grains up to 60 kg N/fed as urea or Enciabien. The results also indicated that there were any significant difference among all the N- treatments in panicle weight, 1000-grain weight and grain yield, while straw yields reached to its maximum under the rates starting with 40 up to 60 kg N/fed as urea or Enciabien. Nitrogen % reached to the highest value in grain yield under the rate of60 kg N/fed as Enciabien and under both 50 and 60 kg N/fed in straw, while nitrogen accumulation was the greatest when rice received 60kgN/fed as Enciabien or 60 kg N/fed as urea in straw. Agronomic efficiency (AE) was the highest under the lowest N-level and reached to the minimum vales under the highest N-rates.