In the research, haemocyte types existing in hemolymph (the liquid consisting of blood and lymph) of Blue Crab’s (Callinectes sapidus Rathbun, 1896) which was captured in Akyatan Lagoon in the North East of Mediterranean region, their amounts in ml and this cells relations with genital and carapace length were defined. Three types cell were identified at the end of the research and these are hyaline, granule and semigranule. The total amount of haemocyte at average ml in female was calculated as 242.300 ±6.113x104, hyaline 25.722 ±0.916x104, semigranule 125.817 ±4.847x104 and the amount of granule was calculated as 91.078 ±3.047x104 whereas in males total haemocyte was calcuated as 216.434 ±4.778x104, hyaline was 21.447±0.609x104 , semigranule was 112,355±3,058x104 and the amount of granule haemocyte was calculated as 82.632 ±2.080x104. In total (male and female) semigranule was dominated with 55% and respectively granule with 31% and hyaline haemocyte with 14 % were dominated. Total amount of haemocyte, hyaline, semigranule and granule haemocyte in females whose average carapace length is 60,715 mm, carapace width is 106,368 mm and weight is 147,884 g was found higher than males whose carapace length is 72.161 mm, carapace width is 126.391 mm and weight is 273.719 g (p<0.05).