The aim of this research is to produce organic liquid fertilizer from sewage sludge and compost containing heavy metals with minimum concentration. By producing such liquid fertilizers, the sewage sludge generated during the process of urban wastewater treatment is recycled and its disposal in the ground is prevented. To meet this purpose, the feasibility of producing liquid fertilizer from sewage sludge and compost as well as the chemical extraction of humic acid was examined. Liquid fertilizers and humic acids were extracted from sewage sludge and compost by NaOH 0.25 M and hydrochloric acids 6 M. Some properties of sewage sludge, compost, extracted liquid fertilizer and humic acid were determined using heavy metals analysis, elemental analysis (CHNOS), nitrogen percentage, exchangeable phosphorous, potassium, EC, Fourrier transform infrared spectroscopy (FT-IR), the light absorption ratio in wave length of 350 nanometer to 550 nanometer (E 3 /E 5 ) and the light absorption ratio in wave length of 465 nanometer to 665 nanometer (E 4 /E 6 ). The results revealed that the amount of humic acid extracted by three extractions from sewage sludge and compost were 13.14 and 6.4 % (%w), respectively. The production of liquid fertilizer by chemically method using 0.25 M NaOH from sewage sludge resulted in significant reduction of heavy metals concentration in the extracted humic acid, while the concentration of heavy metals in the humic acid extracted from compost was not reduced. The amounts of phosphor, nitrogen, and potassium in the produced liquid fertilizers were similar to those in the organic fertilizer. The C/N ratio, FT-IR spectra, and the light absorption in the area of visible wave lengths for both humic acid from sewage sludge and compost were compatible and showed that these humic acids have the aliphatic structure. Thus, they can be better degradated than aromatic compounds in the soil by microorganisms and more available for plants. The humic acid of compost had more aliphatic structure than that of sewage sludge indicating that the time of humification process for compost was short or in other words, the used compost was not mature. The conclusion of this study shows that the production of liquid fertilizer and humic acid from sewage sludge is an efficient method for producing the liquid fertilizer with a high organic matter and low concentrations of heavy metals. Keywords: Sewage sludge, Compost, Liquid Fertilizer, Humic Acid