Here in, the synthesis of Fe 3 O 4 /CdWO 4 and their composite with carbon dot (CD) was achieved by a new method, and convenient procedure using carbohydrates as a reduction and capping agent. The resulting Fe 3 O 4 /CdWO 4 and Fe 3 O 4 /CdWO 4 /CD heterostructure were examined by X-ray diffraction, energy dispersive spectroscopy, field emission scanning electronmicroscopy, vibration sampling magnetometer, and transmission electron microscopy analyses. Fe 3 O 4 /CdWO 4 heterostructure indicated degradation around 49% while composite Fe 3 O 4 /CdWO 4 with CDs can degradation 99% for 80 min under visible light for Rodamin B. Factors influencing 4-nitrophenol elimination via the stated nanophotocatalyst, like size of nanostructures, pH, weight% CDs to Fe 3 O 4 / CdWO 4 and dyes were investigated. The finding showed that Fe 3 O 4 /CdWO 4 / CDs contains accumulation and spherical-like, fine monodispersity, pure structure, and superior magnetic features with particle size around 30 to 50 nm. UV-visible spectroscopy showed a decrease in the band gap of the Fe 3 O 4 / CdWO 4 from 3.15 to 2.70 eV with increasing CDs to Fe 3 O 4 /CdWO 4 nanostructures. In addition, the result showed that with assessment of pH, dose heterostructure and type dyes are able to optimum condition.