This study examines the effect of closed area on woody species regeneration by comparing the woody species regeneration among closure, open woodland, and degraded land areas in Loma Bosa district, Dawuro zone in southern Ethiopia. Results show that Simpson's Diversity Index was 7.24 for woody species in closed area, 6.01 in open woodland and 3.40 in open degraded land area. Shannon-Weiner Diversity Index(H') was 2.26 for woody species in closed area, 2.38 in open woodland area and 1.56 in open degraded land area. The results of Sorenson's similarity coe cients indicates woody species composition in closed area are highly correlated with open woodland areas. Wood species density were 2,225 ha-1 , 1,642 ha-1 , and 297 ha-1 for closed area, open woodland area, and open degraded land area, respectively. The results indicate that closed area development enhanced species composition, richness, diversity, woody vegetation regeneration, inverted J shape Diameter at Breast Height (DBH) and height class and higher woody species density and crown cover class percentage compared to open degraded area. Overall results from this study indicated that area closure is important for improvement of woody species regeneration in the study area. 1. Introduction Land degradation, a process of diminishing the productive potentials of land resources, is one of the serious environmental problems at the global scale (Le et al., 2016; Nkonya et al., 2016). It has been increasing in severity and extent in many parts of the world. For instance, in 2008, the United Nations Food and Agriculture Organization (FAO) reported that more than 20% of all cultivated areas, 30% of forests, and 10% of grasslands undergoing degradation in the world. A recent study by Le et al. (2016) reported that about 29% of the global land area covered by the degraded land, which are affecting about 3.2 billion people who are especially rural communities, smallholder farmers, and the very poor in the developing regions of the world. Land degradation mainly triggered by population pressure, expansion of agricultural land, deforestation, and over-exploitation of the natural resources (Mganga et al., 2015; Yirdaw et al., 2017, Manaye et al., 2019). It is one of the major drivers of declining agricultural productivity, increasing food insecurity, rural poverty, and deterioration of ecological functions in the world (Gashaw et al., 2018). Thus, combating of land degradation though rehabilitation and ecological restoration is important to ensure the long-term productivity of the land resources and survival of life on the earth (Asmare & Gure, 2019; Manaye et al., 2019). Successful land rehabilitation and ecological restoration activities enhances improved land productivity, food security, livelihoods, biodiversity, ecological balance, and other ecosystem services and functions (Mureithi et al., 2014; Reside et al., 2017; Mekuria et al., 2017). Closuring degraded area from human and livestock interference is one of the successful rehabilitation activities to combat land degr...