This experiment was conducted at greenhouse of Horticulture Research Station, Mansoura, Egypt during the two consecutive seasons of 2017 and 2018. The aim of the present work was to improve plant growth, roots traits and chemical constitutes of the sky flower( Duranta erecta var. variegata ) by using humic acid (HA) at the rates of 2,4 and 6 ml/l and salicylic acid (SA) at the rates of 100,150 and 200 mg/l as well as chitosan (CH) at the rates of 100,200 and 300 mg/l.The obtained results revealed that HA, SA and CH applications at any rate significantly improved plant growth characters (plant height, number of branches per plant, fresh and dry weights per plant and leaf area) and root traits (root length and fresh and dry weights of roots per plant) when compared with control. In same time, all application treatments under study significantly increased total chlorophyll content, total nitrogen, phosphorus and potassium percentages in the leaves in comparison with control treatment (untreated plants). The best results in this connection (plant growth, root traits and chemical constituents) were recorded from 300 and 200 mg chitosan/l, followed by 6 ml humic acid/l then 200 mg salicylic acid/l during both seasons.