Abstract: Establishing protected areas (PAs) is internationally recognized as the most effective means of in-situ biodiversity conservation. Since the first nature reserve, Dinghu Mountain in Guangdong, was set up in 1956, China has established nearly 10,000 PAs of various types and levels, with a total area of over 1.85 million km², accounting for about 18.3% of its total land area. It has built a PA system with national parks as the mainstay, supported by nature reserves and supplemented by nature parks (including forest parks, geoparks, marine parks, wetland parks, etc.). After the establishment of the first nature reserve, China set up its first forest park in Zhangjiajie, Hunan Province, and a batch of national scenic areas, including Huangshan Mount in Anhui Province in 1982. In 1996, two national marine special reserves were established in the Miao Archipelago and Qinzhou Bay. The first batch of national geoparks, including the Stone Forest in Yunnan, were established in 2000. In 2005, the first national wetland park pilot was launched in Xixi, Zhejiang Province, and the first national marine park pilot projects were initiated in places like Hailuogang Island, Guangdong Province, in 2011. The first national desert park was established in Shapotou, Ningxia, in 2013, and the first batch of national grassland parks, including Eilechuan in Inner Mongolia, were initiated in 2020. National parks on a trial basis were launched in 2014, and in 2021, China officially designated its first group of national parks, including Three-River-Source National Park, Giant Panda National Park, Northeast China Tiger and Leopard National Park, Hainan Tropical Forests National Park, and Wuyishan National Park. Efforts have continued on key projects, such as the protection of natural forests and protection and restoration of wetlands. Various policies and measures to compensate for ecological conservation, such as compensation for public welfare forests and incentives and subsidies for grassland protection were introduced. These efforts have played a decisive role in biodiversity conservation in China and even in the world. However, on-site protection also faces issues such as a lack of systematic layout in PAs, the absence of an organic collaborative protection system among numerous PAs, and sharp conflicts between protection and development. To achieve the 30×30 target (by 2030, protect at least 30% of land and ocean areas) of the Kunming-Montreal Global Biodiversity Framework and in accordance with the requirements of global and national biodiversity conservation strategies, the spatial pattern of biodiversity conservation needs systematic optimization. This requires national parks to cover approximately 10% of the land area, and the remaining PAs covering another 10% of the land. Additionally, the ecological protection red line, excluding the areas of PAs, should cover around 10% of the land area. Other Effective area-based Conservation Measures (OECMs) can further expand the areas of in-situ conservation by 10% to 20%. Optimize the spatial pattern of in-situ biodiversity conversation centered on a PA system with national parks as the mainstay, supplemented by OECMs, base on the ecological protection red line, and supported by key areas for the protection and restoration of important natural ecosystems, such as natural forests, grasslands, wetlands, deserts, and oceans. In-situ conservation of biodiversity may cover 40% to 50% of the land area. Ensure the in-situ conservation of significant natural ecosystems and key regions for biodiversity protection.