In some late years a number of fibre flax varieties and new breeding lines have been created and investigated at the Upytė Research Station of Lithuanian Institute of Agriculture (LIA). The fibre quality parameters of the new varieties of fibre flax are studied and compared with those of standard flax varieties. Flax was pulled at the stage of early yellow ripeness, warm water-retted, threshed, scutched and hackled. Long fibre content was calculated from the dry mass of unretted straw. Fibre quality’s parameters of some flax varieties (“Belinka” (standard), “Baltučiai”, “Ariane”) and new breeding lines (No. 01057-12, No. 1698-13a, No. 1864-24, No. 1963-3) grown in 2001 – 2003 are investigated. The main properties of flax fibre as fineness, flexibility, and tensile strength are measured, and the data obtained by common methods and some new modern methods are compared. The flax varieties producing the fibre of higher qualities are revealed.