This study was carried out to determine the effects of seaweed (Ascophyllum nodosum) extract applications (control, 2, 4 and 6 cc/l) and drought stress at the different osmotic pressure (control,-0.5 MPa, -1.0 MPa and -1.5 MPa) generated by PEG 6000 on some physiological parameters in Echinacea. The leaf area, leaf chlorophyll content, ion leakage in leaf tissues, malondialdehit level (MDA), relative water content, and membrane endurance index in leaf tissues of echinacea plants were investigated.As a result of the research; leaf area, membrane endurance index and relative water content in leaf tissues decreased under drought stress. It was determined that there was increase in the level of MDA and ion leakage in leaf tissues by the applications. Drought stress did not have any significant effect on the leaf chlorophyll content. It has been determined that seaweed applications had the negative effects on the plant of drought stress. There were positive and increasing effects on the examined parameters such as leaf chlorophyll content and membrane endurance index except for MDA level and ion leakage in leaf tissues of seaweed applications. Seaweed applications did not affect investigated parameters includfing relative water content of leaf tissues and leaf area.