The bioavailability of herbicides in soils is affected by adsorption and desorption characteristics of the soil. The objective of this work was to investigate the behavior of glyphosate adsorption, desorption and bioavailability in agricultural soils and to evaluate effect of adsorption and desorption on bioavailability (mineralization) of the herbicide. Adsorption, desorption and bioavailability experiments were performed using 21 soil types from Germany and Slovenian in the application rate of 10 µg herbicide glyphosate g^-1 soil. Soils differ hugely in soil texture, soil organic matter content, pH, oxalate extractable Al³⁺ and Fe³⁺. The mineralization experiments were conducted under test conditions: water tension of –15 kPa as soil moisture, a soil density of 1.3 g cm^-3 and at 20°C in the dark. Batch experiment from OECD guideline 106 (OECD, 2000) was used to determine adsorption/desorption behaviors of glyphosate in soils. The desorption-biodegradation and mineralization was used to access the bioavailability of glyphosate in the test system. The laboratory results showed that glyphosate was strongly adsorbed, but weakly desorbed in soils. The adsorption and desorption of glyphosate had a big variance among soils. The adsorption and desorption of glyphosate in soils was individually regulated by exchangeable H⁺ and soil pH-CaCl₂. The adsorption of glyphosate in soils was collectively controlled by soil pH-CaCl₂, total carbon content and silt whereas the cumulative desorption of glyphosate in soils was collectively supervised by soil exchangeable H⁺, pH, and Mg²⁺. Moreover, soil textures, soil organic content, P₂O₅, Cu²⁺, oxalate extractable Fe³⁺ and CEC were found not to have any correlation with adsorption and desorption of glyphosate in soils. The desorption of glyphosate in soils had a much stronger positive correlation with the cumulative mineralization of glyphosate than the dissolution of glyphosate.