In order to determination plant density rice cultivars with machine transplanting in Tonokabon Rice Research Institute of Mazandaran in 2009.This experiment laid out as split plot in a randomized complete block design with 3 replication. The main plots were planting space with four (12x30, 14x30, 16x30 and 18x30) Cm and sub plots were rice cultivars (Shiroodi, Kados, Hashemei and Deylamani). During growth stage traits, plant height, Fertile tiller, panicle length, number of grains (filled, unfilled and total) per panicle, 1000-grain weight, biological and economical yield, harvest index and grain yield were measured. Anova showed non significant difference for all characters (except filled and total grains) measured. Effect of cultivars on filled and total grains was significant at 0.05 probability level, effect on plant height, Fertile tiller, panicle length, unfilled grains, 1000-grain weight, biological and economical yield, harvest index and grain yield was significant at 0.01 probability level. The highest grain yield (5787.3 kg.ha-1) was obtained in 18x30 cm planting space. The greatest grain yield (7374.1 kg.ha-1) was obtained for Shiroodi cultivar. Finally, according to the results, 18×30 cm planting space and Shiroodi cultivar was recommended.