Abstract: This is a statistical study of daily dust number observations made at Pei-chi-ko, Nanking, during the years 1933-1936 inclusive. Daily observations were taken at 8h with Owen's dust counter and published serially in the Monthly Mete rologieal Bulletins of the Institute of Meteorology. 9 tables are embodied for average, extreme dust numbers and for various wind direction forces, visibility, humidity and weather, and with discussions.