The present investigation was conducted to identify the major anthocyanins of petals in cyclamen and to make clear the relationship between floral pigment and flower color expression to obtain the breeding aspects for blue flower cyclamen. 1. Four major anthocyanins derived from two anthocyanidins were identified. They were peonidin-rutinoside, peonidin-monoglucoside, malvidin-monoglucoside and malvidindiglucoside, respectively. This is the first case in which rutinoside of peonidin was found to occur in cyclamen petals. 2. Petals which contained peonidin glycoside mainly expressed red to reddish-purple flower color, while those contained malvidin glycoside mainly showed pink to purple. It was shown that the latter gave much bluer tone for cyanic cyclamen petals, than former 3. Malvidin-diglucoside gave bluer tone than malvidin mono-glucoside within malvidinglycoside. 4. The co-pigmentation effect was clealy observed in peonidin-rutinoside group and malvidin-monoglucoside group, although it was not so clear in malvidin-diglucoside group. 5. Co-pigmentation effect was unclear due to low amounts of anothocyanin in malvidindiglucoside group. The aspects for breeding to obtain blue flower cyclamen were discussed.