The present study was conducted during the 2016-2017 at University of Sulaimani, College of Agricultural Sciences. This investigation aimed to study the  effect of humic acid (foliar application) with three levels; 2.5, 3.5 and 4.5 ml/L and three levels of (soil application) ; 1.5, 2.5 and 3.5 ml/L, compared with the control (spray with water only) on growth and yield components of broccoli (Brassica oleracea L. var. corato). After 2 weeks from transplanting, the humic acid was added four times to the plants. The experimental design was used is Random Complete Block Design (RCBD), with three replicates was applied and the means compared according to Dunken at 0.05 level. The obtained results showed that soil application in the rate of (1.5 ml/L) achieved the highest results of Plant height (53 cm), fresh weight of main head (403.5 gm) and total yield (50 ton/ha). On the other hand, the highest value of the main head diameter was obtained by foliar application of 2.5 ml/L. In addition, the highest value of TSS was recorded when humic acid as a foliar spray at a rate of 3.5 ml/L, while the amount of NPK were not significantly affected by applications of different doses of humic acid.  These results imply that soil application of humic acid at the rate of 1.5 ml/L could be recommended to use in the agricultural field for producing optimum yields.