A green alga variant having a dual-specificity tyrosine-phosphorylation regulated protein kinase activity that is reduced compared to a dual-specificity tyrosine-phosphorylation regulated protein kinase activity of a parental strain is provided. The green alga variant increases a total amount of a lipid production per unit time and per unit culture area compared to a total amount of a lipid production of the parental strain. A dual-specificity tyrosine-phosphorylation regulated protein kinase of the parental strain is a protein having an amino acid sequence with at least 50% sequence identity with the amino acid sequence of an active site and a substrate recognition site of SEQ ID NO: 4 and having the dual-specificity tyrosine-phosphorylation regulated protein kinase activity.