The present investigation was carried out at Sakha Agricultural Research Station to compare growth characteristics, yield and its components of four flax cultivars as well as to throw the light on the interrelationship between yield and its components during 2005/06 and 2006/07 seasons.                 Results of the combined analysis of the two seasons showed that significant differences were observed among the three commercial varieties Sakha 1, Sakha 2 and Sakha 3 and strain 16 in dry weight/plant, leaves and stems percentage at 90 and 120 days after sowing. Significant differences among the four flax cultivars were observed for apical branches and capsules percentage at 120 and 150 days after sowing. Flax strain 16 gave the highest dry weight/plant at all growth stages (60, 90, 120 and 150 days after sowing), followed by the commercial variety, Sakha 2. Meanwhile,  Sakha 3 variety gave the lowest dry weight/plant in most growth stages.                 Comparative study on yield and its components showed that the commercial variety Sakha 1 gave the highest straw yield/feddan, followed by variety Sakha 3. However, Sakha 3 variety exhibited the highest total stem length, technical stem length, fiber yield/plant and feddan, fiber length and fiber fineness. Flax strain 16 had the highest seed yield/feddan, number of seeds/capsules and seed index, followed by the commercial variety Sakha 2.                 Correlation coefficients calculated between straw yield/plant and total stem length, number of apical branches, number of capsules and fiber yield were positive and significant in all cultivars. Moreover, seed yield/plant exhibited significant positive associations with number of apical branches, straw and fiber yields, number of capsules and seeds in all studied cultivars.