[Show abstract][Hide abstract] ABSTRACT: Crossability among seven evergreen azaleas (Rhododendron spp.) in subsection Tsutsui was compared. Capsule set was observed in all the crosses. Numver of seeds per cupsule was lower in the cross with R. kiusianum or R. serpyllifolium than in other crosses, and small flofers with short style andsmall ovary may be the reason for lower number of seeds. Number of seeds per cupsule was maximum when male/female style length ratio(SLA) was around 0.7. The number gradually decreased as the increase of SLA, and above 2.2 of SLA resulted in <200 seeds per cupsule. The seeds germinated very well in the most crosses. In the crosses with R. serpyllifolium, however, unilaterial cross incompirablility was observed.