The concentration of four alkaloids (sanguinarine, chelerythrine, protopine and alpha-allocryptopine) in the aerial parts of snowpopy (Eomecon chionantha) collected from April to August in 1996 were determined by capillary electrophoretic method. The results show that the change of contents of alkaloids according to months is similar to that of the underground parts of snowpopy, i.e. the contents of sanguinarine and chelerythrine wrer lower in June than other months; the contents of chelerythrine were higher than that of sanguinarine and alpha-allocryptopine were higher than protopine.