This superior zoysiagrass line was selected from the zoysiagrass genetic resources collected in the Republic of Korea. Inflorescences of Zoysia matrella lines were collected near the border between wild Zoysia japonica and wild Z. matrella on Jeju Island. Various Z. matrella×Z. japonica lines were obtained using the seeds from the collected inflorescences. In 2021, one of the lines that extended the greening period during the low temperatures of winter was registered under the name of ‘Halla Green 10’. The main morphological characteristics of this cultivar, which were analyzed using the test guidelines of the Korea Forest Service, are as follows: short length of plant (12.01±0.57 cm), short length of leaf blade (8.83±0.68 cm), and short length of leaf sheath (1.71±0.20 cm). The short length of leaf sheath makes it easy to manage the turf grass with low height. Due to the presence of trichomes on the leaf surface and medium-leaf type (leaf blade width: 3.0±0.16 mm), ‘Halla Green 10’ is morphologically classified as Z. matrella×Z. japonica. As the leaf angle is very wide at 77.7°, it has a high photosynthetic efficiency. The colors of the leaf sheath, leaf blade, and stolon are light green, green, and light purple, respectively. In particular, during the low temperature period of winter, the chlorophyll content of the leaves of ‘Halla Green 10’ shows about 7.5-fold from that of the control Z. japonia ‘Yaji’ and about 3.2-fold increase from that of the control Zm-6. Extending the greening period phenotype is expected to be commercially useful (Registration No. 246).