<p><em>The study </em><em>of population biology </em><em>of mud crab <span style="text-decoration: underline;">Scylla</span> <span style="text-decoration: underline;">serrata</span> is necessary to </em><em>analyse </em><em>the population dynamics, </em><em>such as </em><em>growth of crabs, size distribution, mortality </em><em>and exploitation </em><em>rate</em><em>s</em><em> </em>of<em> </em><em>S. </em><em>s</em><em>errata. </em><em>Population biology </em><em>data collection </em><em>was </em><em>carried out</em><em> from March to June 2016 at</em><em> estuary and </em><em>s</em><em>ilvofishery area</em><em>s of three stations (</em>Mayangan, Tanjung Tiga and Blanakan villages)<em>.</em><em> </em><em>Data were analyzed </em><em>using </em><em>analytical methods </em><em>of</em><em> FISAT-II (FAO-ICLARM Stock Assessment Toool II)instruments. </em><em>The results showed the growth of S. </em><em>s</em><em>errata male in Subang distric was </em><em>positive </em><em>allometric and the female was negative allometric</em><em>. </em><em>Growth coefficient (K) ranged from 0.21 to 0.43 in the estuary and from 0.28 to 0.89 in silvofishery area.</em><em> Exploitation rate in</em><em> the </em><em>silvofishery </em><em>area </em><em>has been </em><em>above the maximum exploitation rate. The size distribution of S. </em><em>s</em><em>errata in Subang district has the highest frequency </em><em>at</em><em> </em><em>class</em><em> interval</em><em> of</em><em> 106-110 </em><em>mm </em><em>(male) and</em><em> of</em><em> 101-105</em><em> mm</em><em>. </em><em>The highest abundance of mature female crabs is in May.</em><em></em></p><p><strong><em>Keywords</em></strong><em> : </em><em>population </em><em>biology, </em><em><span style="text-decoration: underline;">S</span></em><em><span style="text-decoration: underline;">cylla</span></em><em> <span style="text-decoration: underline;">serrata</span>, Subang District</em></p>