In order to study the effects of row spacing, planting date and cultivar on changes of leaf area index, dry matter accumulation and allocation of faba bean (Vicia faba L.) this experiment was carried out based on splitplot factorial arrangement in randomized complete block design with four replications at the farm of Gorgan University at 2011-12 . The distance between rows (30, 45 and 60 cm) were assigned as the main factor and factorial of planting date (November 24^th and December 2^nd 2011) and cultivar (Barecat and France) were considered as a sub-plots. Maximum dry weight values of faba beans from cultivation date of November 24^th for row spacing of 30, 45 and 60 cm were 1072.6, 892.6 and 733.5 grams m² respectively which are reduced for 818.42, 521.7, 593 grams per m² values at December 2^nd respectively. The results showed those stages of emergence to the beginning of  fast growth of plants, the beginning of  fast growth of plants to the beginning of seed filling and the beginning of seed filling to maturity were three distinct stages of  changes of dry matter distribution coefficients. Maximum distribution of coefficient for leaf (0.847) at first phase and cultivation date of December 2^nd and row spacing of 45 cm (Barecat cultivar), maximum distribution of coefficient for stem (0.529) at first phase and cultivation date of November 24^th and row spacing of 45 cm (France cultivar) and maximum distribution of coefficient for seed (0.638) at third phase and cultivation date of December 2^nd and row spacing of 45 cm (France cultivar) were obtained.