Research was conducted in Gaung Anak Serka River Sub - Province Indragiri Hilir in October till Januari 2008 as a mean to know status of quality of teritoral water of Gaung Anak Serka River evaluated from physics and chemical parameter, and community structure of makrozoobenthos. The methods used of survey and intake of sampel taken twice, in each station of sample taken at 3 dots at random. Research station consist of; station 1 (GAS river estuary), station 2 (Teluk Pinang), station 3 (Dusun Murni), station 4 (Teluk Pantaian), station 5 (Sungai Iliran), station 6 (Teluk Sungka), Station 7 (Tuasan),station 8 (Dusun Pergam), station 9 (Sungai Empat) and station 10 (Rambaian). Data has taken of quality of water either throughphysics and chemical parameter and also makrozoobenthos. Data of exsitu analysed in Laboratory Faculty of Fishery and Marine Science of Riau University. Quality of physics water parameters (tempaerature, brightness, current flow) sill normal in a condition according to PP.82. year 2001, except brightness for station resideng in part of downstream (station 1-5) have passed normal still. Chemical parameters (pH,DO.TSS.COD.BOD,Nitrate and fospat) also stay in normal gyration. While, organism of macrozoobenthos found in river consist of 6 set of relatives, 5 class and 6 ordo. Set of relatives consist of Tucideae, chironomideae, Baetidae, Ctenodrillidae. Donacidae and Nassariidae. Class covers oligochaeta, insecta ,polychaeta,Pelecypoda and Gastropoda. Ordo Nematoda, Doptera Ephemerptera, Ctenodrilida, veneridae and Neagastropoda. Types of Macrozoobenthos are Tubifek sp, Sp Chironomous, Baetis Sp , Ctenodrillus Serratus and Cyclop neritae.