In order to evaluate the effect of foliar application of humic acid on yield and yield components of red bean cultivars this experiment was conducted at Agricultural Research Station of Arak in 2014. The experiment was in split plots Completely Randomized Block Design (CRBD) with three replications. Three level of humic acid i.e. 0, 1.5 and 3 liters per hectare in main plots and three cultivars of red bean i.e. Derakhshan, Goli and D81083 were in sub plots used as treatments. Results of study revealed that line D81083 along with 3.0 liters per hectare of humic acid application shows superiority over the other treatments and showing 13622 kg per hectare final biomass yield. Among various tested cultivars, the lowest biomass yield (10311.1 kg/hectare) was obtained from Derakhshan cultivar without humic acid application. Further, amongst various tested doses of humic acid, highest seed yield (4253.7 kg/hectare) was reported from the cultivar line D81083 at 1.5 liter per hectare of humic acid application while the lowest yield obtained in Derakhshan without humic acid. Results of current study revealed relationship between bean cultivars and humic acid application and interaction of these two affect the yield and yield attributes of red bean.