Coagulation-flocculation has been considered as an effective method for various water and waste-water treatment at the first stage to remove turbidity, total suspended solids (TSS) and chemical oxygen demand  (COD). Polymeric coagulants isolated from plants are new alternatives for synthetic coagulants as they are highly bio-degradable, non-toxic, noncorrosive, less sludge voluminous and pH independent. The aim of this study is to check the ability of Cassia fistula seed gum coagulants (MHY) in fish processing’s effluent treatment. Jartest experiments were done for two sources of wastewater from two different factories to figure out coagulants dose by considering the changing in color, TSS and COD removal by using PAC as coagulant and with the aid of MHY. The first main parameters varied from 2624 - 2683 mgO2/L for COD, 580 - 571 mg/L for SS and 333.72 - 334.09 Pt-Co for color intensity. Results obtained indicated the best dosage of PAC is 480 mg/L, and with supplement of 4 mg/L MHY it could remove 70.54 - 80.50% of COD, 68.34 - 70.12% of SS and 35.94 - 37.01% color. Natural products such as Cassia fistula seed gum have been use as auxiliary coagulant in coagulation-floccula-tion process to improve the quality of fish processing wastewater.