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. After separating the samples as sexes, some indices such as total length, total weight, claw weight and abdomen meat weight were measured. The results of this study showed, there is a power relation between length and weight indices in different parts of 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.