Studies were conducted in film-mulched cotton fields in 2001 in China to investigate the effects of aphid damage on cotton growth, seed cotton yield and benefits. Aphids were controlled by chemical spraying (of an unidentified pesticide) and artificial inoculation. Aphid damage significantly affected cotton growth, seed cotton production and benefits. Regression analysis showed that the cumulative number of aphids/plant increased by 10 000 and the average boll retention decreased by 4.9%.