The aim of this research was to find out the level of copper and cadmium metals toxicity by deterraining value LC50 - 48 hours to sea horses, therefore we can know the concentration value that is required to eradicated 50% of test organism. This research used experimental laboratories as the method by giving 6 various concentration for every metal, for metal Cu : 0 ppm, 1,584 ppm, 2,509 ppm, 3,…