Persian walnut (Juglans regia L.) is an important nut crops that is under extension, including in Iran. A program was started in the past two decades to select national superior genotypes for using as walnut cultivars. About 50 superior genotypes were selected among seed originated trees in three different phases (groups). The first group consisted of seven selections (Z67, Z53, B21, Z63, K72, Z30 and Z60), which were planted for advanced evaluation with ‘Serr’, ‘Hartley’, ‘Pedro’, ‘Lara’, ‘Franquette’, ‘Ronde de Montignac’, ‘Vina’ and ‘Chandler’ in a α latis experimental design with two replications and 4 trees per plot in 1994 in Karaj. The evaluation of leafing date, pistillate flowering (start and end) and pollen shedding period (start and end) in 15 cultivars/selections (c/s) were done during 2005 - 2008. The data showed that among the 15 c/s; Z30 and Z53 are protogynous, ‘Ronde de Montignac’ tends to be protogynous and the others were protandrous. The leafing date was very variable so that Z53 showed to be the earliest, leafing two days before ‘Serr’. B21, K72, Z30 and Z60 had the same leafing time of ‘Serr’. The Z63 and Z67 showed to be 1 to 3 days later leafing than ‘Serr’, while ‘Vina’, ‘Pedro’, ‘Lara’, ‘Hartley’ and ‘Chandler’ 6 to 9 days Later. ‘Ronde de Montignac’ and ‘Franquette’ showed to be the latest cultivars leafing respectively 16 and 18 days after ‘Serr’. Regarding the male and female flowering, Z30 and Z53 showed to be good pollenizer for ‘Serr’, Z60, Z63, K72; while the ‘Ronde de Montignac’ showed to cover well the pistillate flowering period of ‘Hartley’, ‘Chandler’, ‘Pedro’ and ‘Lara’.