Paeonia ostii ‘Fengdan’, Paeonia rockii ‘Ziban’, and Paeonia suffruticosa ‘Xiangyu’ are important species of tree peony (Sect. Moutan DC., Paeonia) with not only medicinal and ornamental values, but also their high seed oil contents. Peony seeds have a deep dormancy, which greatly restricted their propagation. In this study, breaking of both hypocotyl and epicotyl dormancy in excised embryos of three tree peony species described above as affected by light and its quality was investigated. The excised embryos were cultured in the Murashige and Skoog medium containing 30 g·L-1 sucrose and 8 g·L-1 agar, but any plant growth regulators. They were cultured for 8 weeks at day/night temperatures of 24/18°C under either dark or one of three qualities, red (650 nm), blue (450 nm) or a 1:1 mixture of red and blue, of light provided from light emitting diodes at an intensity of 50 µmol·m-2·s-2 photosynthetic photon flux density. The breaking of both hypocotyl dormancy and epicotyl dormancy was affected by light and its quality in all three species. The blue light suppressed breaking of hypocotyl dormancy, but accelerated breaking of epicotyl dormancy. The red light had a similar effect on breaking of hypocotyl dormancy as with a dark condition, while the red light suppressed breaking of epicotyl dormancy. All those effects were most pronounced in the Paeonia rockii ‘Ziban’ among the three species tested. In a conclusion, breaking of dormancy in seeds of these tree peonies could be accelerated by treating the seeds first with dark or red light for accelerated breaking of hypocotyl dormancy, followed by blue light for accelerated breaking of epicotyl dormancy.