Two field experiments were conducted at Research Farm of Rice Research and TrainingCenter, Sakha, Kafr El-Sheikh, Egypt during 2010 and 2011 seasons. The study aimed to evaluate the effect of Cycocel (CCC), a mixture of Cycocel and Dicloro Iso Butyric acid (DCIB) (MLU 208), Triapenthanol (RSW041I) and Uniconazole on physiological and growth behavior of rice plants, as well as lodging degree of Sakha 104 rice cultivar(long stem cultivar that is characterized by high rate of lodging).The most important results showed that CCC did not exhibit any significant retarding effect on rice plants .All levels of MLU 208, RSW04ll and Uniconazole markedly decreased the height of plants in the terms of decreasing its lodging degree. Number of tillers/m², flag leaf area and dry weight of rice plants were increased under all growth retardants except CCC. Degree of lodging was decreased by the application of proper levels of MLU 208, RSW04ll and Uniconazole. RSW performed better regarding lodging and reduced it to 75% of the control. All growth retardants increased the concentration of Chlorophyll A and Chlorophyll B in rice leaves but caratenoids were decreased. Nitrogen concentration in shoots and grains was increased while K was decreased. GA₃ concentration in shoots was decreased but ABA was increased by the application of MLU 208, RSW0411 and Uniconazole. The high levels of growth retardants increased the weight of l000-grain, starch and protein yields. Grain yield was the highest when   Uniconazole, MLU 208and RSW041Iwere applied, respectively.