The objectives of this study were to convert marigold dregs to a cationic metal ions and dye adsorbent and further to investigate the potential of using the adsorbent for the removal of copper(Ⅱ) and methylene blue (MB) from effluents. The base washed marigold dregs and citric acid (CA) modified marigold dregs (MMD) were prepared and the structure were investigated by fourier transform infrared, emission scanning electron microscope and X-ray photoelectron spectroscopy. The results show that the modification did not significantly change the morphology of the dregs surface structure but the esterificated reaction could increase the carboxyl groups and hydroxyl groups on the surface of the adsorbent. The adsorption ability are also evaluated by MB and copper(Ⅱ) and the results show the MMD is an excellent adsorbent. Due to the high adsorption quantity, it may be used as a low cost alternate adsorbent for the elimination of metal and dye ions form effluents.