The development of Neolithic cultures in China coincided with the arrival of the Mid-Holocene Climatic Optimum. The warm and wet climatic conditions enabled the flourishing of small villages in major river valleys, from the northeast to south China. These settlements’ archaeological remains are characterized by dwellings, storage pits, burials, and, sometimes, by ditched or walled enclosures. Domestication of plants and animals is clearly evident, and ritual activities are reflected in burials and on artifacts. Pottery vessels are prevalent. Polished stone tools increase in proportion, but chipped stones and microliths continue to be found. Grinding stones (slabs, handstones, mortars, and pestles) are common in toolkits. The mopan slabs and mobang elongate handstones, often occurring together in the archaeological context, now became a diagnostic tool complex in the toolkits, particularly in North and Northeast China.