The cotton bollworm, Heliothis armigera (Hubner), occurred in unparalleled outbreaks in the Yellow River Valley cotton region in North China in 1992. The great changes in habitat, food, natural enemies, weather and control efficiency are believed to be the major causes. From the standpoint of the food chain, we stress the factors of increased food resources and decreased control efficiency. It is predicted that this pest population will keep increasing in the near future as the rural economy develops irreversibly and favorable weather comes stochastically. Rapid development of a new kind of insecticide is unlikely. An improved control depends largely on how well the present measures are assembled and popularized. There is a need for a region-wide cooperative research and extension program.