Antioxidant or prooxidant activity of ${eta}$-carotene was studied in autoxidized or methylene blue photosensitized lard using the depletion of headspace oxygen, p-anisidine value (p-AV), or a modified DPPH methods. ${eta}$-Carotene of 1.25 and 2.50 ${mu}M$ significantly decreased headspace oxygen and ${eta}$-carotene from 0.25 to 2.50 ${mu}M$ increased significantly p-AV in lard oxidized at $60^{circ}C$ for 60 h (p<0.05), implying ${eta}$-carotene acted prooxidantly. ${eta}$-Carotene under 0.25 ${mu}M$ in oxidized lard did not decrease the absorbance of DPPH significantly (p>0.05), while 1.25 and 2.50 ${mu}M$ ${eta}$-carotene decreased the absorbance of DPPH significantly (p<0.05), indicating ${eta}$-carotene over 1.25 ${mu}M$ accelerated the formation of radical scavenging compounds from oxidized lipids (RSOLs). However, all the concentration of ${eta}$-carotene did not cause significant changes in DPPH absorbance and headspace oxygen content (p>0.05) in photosensitized lard at $40^{circ}C$ for 24 h, indicating antioxidant properties of ${eta}$-carotene in photosensitization.