Abstract: Based on the historical records and the recent research, the author tries to give a brief account of the change of dominant species of house rats and mice.According to the investigations in 1966 and in 1978, there are three species of house rodents at Xiamen i.e. Rattus norvegieus, R.flavipectus and Mus musculus.The date collected including the years 1933, 1935, 1936, 1954-1962, 1964-1966, 1974 and 1978, show that the population of R.norvegieus had always been in a higher level for the last years of 50's. Since the middle of the 50's, the population of R. flavipectus had undergone a rise-fall procees, while the population of Mus musculus has been rising。and by the 70's it has become the dominant species. Therefore we may devide the change of the dominant species of house rats and mice into three stages.Through analysing and comparing the weather, the house structure, the population and the change in living conditions, the author believes that the changements are mainly connected with the improvement of the inhabitation conditions and the activities of human benigs.The author is of the opinion that Mus musculus and R.norvegieus are the principal species that should be prevented and controlled henceforth. To improve the sanitary condition of the people's living surroundings; to clean the cloaca; and to improve the technique in poisoning rats, are the main measures to prevent the attack of house mice. Autumn and winter are the best seasons to eliminate the mice.