A eukaryotic microalga, Asterarcys quadricellulare KNUA020, was isolated from garden soil at Kyungpook National University in Daegu, South Korea and its biotechnological potential was assessed. Optimal growth was obtained when the culture was incubated at $25^{circ}C$ and around pH 7.0. The total lipid content of the isolate was 15.5% of dry weight and its most abundant fatty acid was nutritionally important C18:3 ${omega}3$ (${alpha}$-linolenic acid, ALA). In addition, a high-value fatty alcohol, hexadecenol ($C_{20}H_{40}O$), was also identified in this photosynthetic microorganism. Hence, A. quadricellulare KNUA020 appears to be promising for use in the production of microalgae-based biochemicals.