The chemical composition variations of the Black pomfret (Parastromateus niger) from Ratnagiri coast were investigated seasonally over the period of three year (2008-2011). Protein in female muscle from Sakhri-Natye is recorded 20.155±0.309 within PFZ while from outside PFZ is 19.278±0.309 as compared to male during November-December. On the other hand in March-April from female muscle is noticed 21.032±0.404 for within PFZ than outside PFZ is 21.167±0.710 as compared to other two fish landing centers. Glycogen level in female liver from Harnai within PFZ is 16.097±0.170 whereas from outside is 15.104±0.214 when validation experiment compared to all the males during November-December. From female liver value is noticed 16.550±0.214 from within PFZ, as for outside PFZ 16.153±0.298 as compared to male. Lipid level from female gonad Harnai region 8.813±0.612 for within PFZ as for outside value is 7.108±0.371, while for Mirkarwada for within PFZ male gonad the value is observed 7.758±0.486, for outside is 7.190±0.506 during November-December. In March-April from within PFZ for female gonad Harnai value is 10.03±0.782, for outside PFZ is 8.894±0.612, whereas from male gonad from Mirkarwada within PFZ region is 9.056±0.371, while for outside PFZ is 7.758±0.486 as compared to other landing centers during March-April respectively. The Black pomfret fishes caught in both within and outside PFZ areas were in the size range of 25- 32cm. On the whole of it all observations made through within and outside PFZ realm it was concluded that most of the females attain first maturity at 28-32 cm whereas the males at 25-30 cm.