Transport of bacteria through subsurface environment was studied from different perspectives, including the fate of genetically engineered microorganisms in the environment, waste management, public health, microbially enhanced oil recovery and in-situ remediation of contaminated subsurface. The objective of this study was to investigate transport and sorption of bacteria in saturated sandy loam. Escherichia coli and Cl^-1 tracer solution were introduced separately into saturated soil columns as a pulse function under steady water flow. A mathematical model based on one-dimensional convection-dispersion equation (CDE), including the local equilibrium assumption and non-equilibrium assumption, was formulated to describe E. coli's transport. The CXTFIT program was used to fit mathematical solutions of different theoretical transport models, based upon the CDE, to experimental results. The results show transport of E. coli through sandy loam was well described by the chemical nonequilibrium two-sites model when a first-order kinetic removal process was assumed. Bacteria were removed at a significantly greater rate than Cl^-1 tracer. Breakthrough Curve (BTC) of E. coli was retarded and had a longer elution tailing when it was compared with that of Cl^-1 tracer, and the relative concentration of E. coli at the peak of BTC was much lower than that of the tracer. The total breakthrough of E. coli was also much smaller than that of the tracer. The increase in flow velocity from 0.214 to 0.470 cm min^-1 resulted in marked increase in E. coli from 0.05 to 0.2 at the peak of BTC, but decrease in retention coefficient.