Abstract: (1)The flowering habit of the Flax with sterile nucleus is more or less like common Flax. (2) Flowering colour of the Flax is pale purple,seed vessel colour is app-roximately to white,but the flowering colour of fertile Flax is dark purple, seed、essel colour is brown.So we can easily distinguish sterile Flax from fer-tile one.This is very convenient to selection and use. (3) Stigma's viability can remain for 3 to 4 days and flourishing in: to 2 days after flowering.The viability of the pollen stored in refrigerator at 3 to 8 C or in the field can remain respectively for 4 to 6 days and 3 to 4 days. It can prolong for 3 to, days when preserved in the room.It w ould be better if we could pollinate in two days after flowerinng. (4) The seed-producing rate of cross-fertilization of sterile Flax is lower than fertile one,and the seed-producing number per fruit is less also.

Key words: Sterile nucleus, Flax, Flowering habit, Hybridization