The operations of EA conflo IV and DELTA V Plus to measure the stable isotope ratios of carbon and nitrogen were proceed during the Lecture of Stable Isotope Ecology 2010 in the Center for Ecological Research, Kyoto University, Japan. Fifty samples of demersal and midwater fishes collected from southwestern Taiwan were measures and these results were presented as poster in International Symposium on Isotope Ecology 2010 in Kyoto during November 2-3, 2010.