The main features of the whistlers, which were observed at Sanya (18.24°N, 109.5°E; Geomag. Lat. 7.04°N) early in 1983 are described. Agreat number of whistlers were recorded in the observations, including short whistlers, multisource whistlers, and mu-ltipath whistlers. Some of them (about 10%) have the low cutoff frequencies as low as nearly 0.8 kc/s. In addition to the conclusions given in papers [1,2], we further find: (1) the whistlers at Sanya almost always occured during f0
decreasing and the maximum values o'f whistler occurrence rate appeared just at the time when f0
decreased most fast, that is, when electron density changes most drastically. (2) the relation between whistler activities and magnetic storms at low latitudes have some differences with that at medium and high latitudes. Sometimes the correlations are reversed. To explain, all these, further observation and study are required.