Seawater is a renewable natural resource that is easy to get for use in various purposes. Seawater has many mineral deposits, one of which is MgCl 2 . This research aims to synthesize Mg/Al-NO 3 hydrotalcitelike with Mg raw material from seawater, characterization and test the adsorption capacity to Cu 2+ and Cr 6+ metals. Mg/Al hydrotalcite-like synthesis with NO3 interlayer was performed on a 2: 1, 2,5: 1, 3: 1-mole ratio with pH 10 for 1 hour coprecipitated. Characterization of Mg/Al-NO 3 Hydrotalcite-like using Atomic absorption spectrophotometry (AAS), X-Ray Diffraction (XRD), XRF(X-ray fluorescence spectrometry), Surface Area Analyzer (SAA). The hydrotalcite-like adsorption power application was tested against Cu 2+ and Cr 6+ metals. The results showed that Mg/Al-NO 3 Hydrotalcite-Like formed at d003, d006, and d110 were 8,55, respectively; 3,86; and 1,51 Ǻ according to the ICDD Hidrotalsit Mg/Al-NO 3 standard, and the area covered by SAA was 132,081 m 2 / g, with compositions tested by XRF on Mg(OH) 2 and Al(OH) 3 were 11,5 g/ml and 20,3 g/ml, respectively. Hidrotalsit Mg/Al-NO 3 adsorption Cu 2+ occurred of 3,63 mg/g at 30 min contact time and Cr 6+ metal of of 0,75 mg/g at contact 60 minutes.