A field experiment was conducted during 2011 season at Al-Mishkhab Rice Research Station at Al Najaf Governorate. The objective were to study of field standard and laboratory for main three rice cultivars (Amber33 , Jasmine, and Furat 1)with four seed class (Foundation seed , Registered seed , Certified seed , and Commercial seed). The experiment design was used split plots with RCBD arrangement in three replications. The study showed that the Furat 1 and Jasmine was gave higher grain yield than Amber33 (6165kg.hˉ¹), (5576 kg.hˉ¹)and(4723 kg.hˉ¹) respectively. The result showed that off type plants numbers in 10mˉ² and off type seeds in 100 gm was increased whenever the seeds class decreased. The commercial seed class gave higher of off type plants number , while foundation seed class gave the lowest(7.4plant/10mˉ²) and(1 plant/10mˉ²) respectively. Whereas commercial seed class gave the higher seed off type and the foundation seed gave the lowest reached to (120.3 seed/100gm) and(11.7 seed/100gm) respectively. The off type plant number to Furat 1 cultivar gave (4.7 plant/10mˉ²), while the lower off type plant for Amber33(3.3 plant/10mˉ²), while the off type seed number of Furat 1 and Amber33 gave (70.7 seed/100gm) and (40.8 seed/100gm) respectively. Data also revealed that the higher off type plant number of Furat 1 cultivar (9 plant/10mˉ²) was associated with commercial seed class. The lower off type plant number of Amber33 (1 plant/10mˉ²)to foundation seed class , and the higher off type seed number of Furat 1 (154 seed/100gm) was associated with commercial seed class, while the lower off type seed number of Amber33(8 seed/100gm) with foundation seed class. The study showed that the off type plant and seed numbers was increased in same seed class when increased of productivity for all cultivars. Also there were significant difference between off type plant and seed numbers, then, was increased in same seed class when the productivity was increased also to all cultivars. The Furat 1 and Jasmine (High of grain yield) gave the higher of off type plant and seed numbers for commercial , registered, and certified seed class respectively compare with Amber33 (low of grain yield).