In order to investigation of growth pattern and body weight-length relationship of narrow clawed crayfish, Astacus leptodactylus in different stages of its life, approximately 10000 newborn crayfish were released in earthen pond. This pond had the similar condition to their habitat. Sampling was done during four stages of their life, under 2 months and 4, 6, 15 months among crayfish population between 1385-1387 years. After separating the samples as sexes (294 males and 259 females), some indices such as total length, total weight, claw weight and abdomen meat weight were measured. The results of this study showed, the mean total weight and length were between 0.15 to 11.76 g and 18.5 to 76.20 mm respectively in male of different age stages, while these indices were measured in female 0.15 - 11.49 g and 18.5 -76.14 mm respectively. There were no significant differences between mean total weight and length values in male and female (p>0.05). There is a power relation between length and weight indices in different parts of the crayfish body for male and female. The growth pattern in experimental crayfish was isometric while the claw growth pattern was observed as allometric in male according to this relationships and regressions analysis.