Abstract: Small features are a key factor affecting monitoring crop area using remote sensing on a large scale. Taking Hebei Province as a study area, stratified sampling method for reference and zonal sampling method were applied to process small features sampling frames in crop land under different conditions with 99 in all. Finally, a series of estimation values of area ratios of small features were obtained in Hebei crop land. Thereinto, 10.15% in paddy field, 3.51% in plain, and 7.14% in sloping crop land. Precision of surveying results by remote sensing in Hebei Province could be improved with the data. And the result has much practicability and usage for surveying crop land in Hebei Province by means of remote sensing. It also has important references for the similar areas.