Abundant charred plant remains were unearthed from the late Neolithic Lutai site. Only foxtail millet and common millet were found, indicating of a pure millet agricultural economy during Yangshao period. New crop soybean (Glycine max) emerged in the following Longshan period and the agricultural economy became complex. Based on quantitative analysis of millets and weeds of Longshan period, the ratios of immature to mature millet grains and weeds to millets reveal that early stage crop-processing (threshing and winnowing) and possible late stage crop-processing (dehusking) were conducted by independent nuclear family in separated zones of Lutai settlement. Combined with other archaeobotanical and stable isotope studies in northern area of Henan Province, only millets were cultivated in this region during the Yangshao period. In the following period of Longshan new crops including rice, wheat and soybean were cultivated or utilized and multiple-cropping agricultural system was established in northern area of Henan Province and other areas of Henan Province alike. Besides, landforms, settlement conditions and the choices of specific population contributed to the differences in agricultural patterns among the sites in northern area of Henan Province.