A field experiment was conducted at El-bostan Farm, Faculty of Agriculture, Damanhur University in the two successive summer seasons of 2018 and 2019. The aim of this study was to investigate the effect of humic acid application on sunflower (Helianthus annuus L.) growth, yield & its components and some chemical constituents grown under saline soil conditions.The experiment was laid out in a split plot design in four replicates. The main plots were occupied by three sunflower genotypes Sakha 53, Giza 102 and Line 120. While subplots contained four treatments of humic acid (HA) i.e.; without HA (control), HA soil application, foliar HA spray and a combination of both foliar spray and soil addition of HA. The results showed that, different genotypes did not perform similarly under salinity stress conditions. Line 120 had the highest leaf area/plant, head diameter, seed yield/ plant and seed yield/ha. With regard to humic acid application, it caused improvement for most growth, physiological parameters, yield and its components compared to control. Obtained results also, showed that humic acid application as both soil and foliar spray on Line 120 and Sakha 53 led to obtain the highest values of most studied parameters in the two growing seasons. Finally, it could be concluded that humic acid application can ameliorate negative effects of salinity on sunflower.