Maliki, MuhammadDedi AfandiAdnan Kasry2013-07-272013-07-272013-07-27http://repository.unri.ac.id:80/handle/123456789/4778Diatomea investigation in the body of drowning victims is one of important investigation to determination the drowning victims location. Diatomea is sould in the lung or another organ from the body of victims as prove of drowning intra-vitality it means the victims are still alive when they are in the water and they are dead because of it. Diatomea species determining can be concluded as a supporting diagnose to identify the location of drowning victims by comparing the diatomea in the victims body with diatomea species in the water this research is a descriptive research which is purposed for recognizing the species and the diatomea abundant in the Rokan’s River Estuary of Bangko Sub-district and Batu Hampar Sub-district Rokan Hilir Regency this research sample is taken from five research of stasions as purposive sampling. This research was done in April and May 2013 at Rokan’s River Estuary in Sub-district Bangko And Subdistrict Batu Hampar Rokan Hilir Regency. Diatomea investigation was done by using Binocular microscope. This determining was done by using Masaharu and Yunfang atlas the abundant was searched by counted and numbered by using American Public Health Associations (APHA) formula. Diatomea was founded eight species they are: Aulocoseira sp, Diatoma sp, Nitzchia sp, Isthmia sp, Melosira sp, Navicula sp, Skeletonema sp, Bitdulphia sp. The abundant of diatomea is founded 11152,2 sel/L when the water comes up and I found 9132,6 sel/L when the water come down with the Diatoma sp as the most dominant diatomea as a mount as 4986,4 sel/L when the water comes up and with diatoma sp as the most dominant Diatomea as amount as 3799,8 sel/L.otherRokan’s river estuary drowningspecies and abundant diatomea