Bio-calcite cement and portland cement can release ammonia and carbon dioxide respectively, and these gases have a negative impact on the environment.In response to these aspects, a new binder should be selected to cement loose particles, and bio-phosphate cement (microbial induced deposition phosphate) was taken into our consideration due to the presence of phosphate minerals in the nature.In this research, phosphate-mineralization microbe was selected as the suitable microorganism, and which could produce alkaline phosphatase (EC 3.1.3.1) that constantly hydrolyzed phosphate monoester in bacterial solution, then PO43-/HPO42-is obtained.MHPO4,MPO4, M3(PO4)2, etc.were prepared when phosphate reacted with metal cations.It is showed that the strength of bio-sandstone cemented by the biological barium phosphate is better than biological phosphate calcium and magnesium when mechanical properties of bio-sandstone are compared through different bio-phosphate cement cementing.This paper confirms the feasibility of bio-phosphate cement binding loose sand particles and presents results from laboratory researches on the influence of standing time and content of biological barium phosphate on the mechanical properties of bio-sandstone.Cemented mechanism of bio-phosphate cement was systematically studied through Fourier transform infrared spectroscopy (FTIR), X-ray photoelectron spectroscopy (XPS) and thermogravimetric-differential scanning calorimetry (TG-DSC).Based on cementation characteristic of bio-phosphate cement, this method can significantly improve the mechanical properties of bio-sandstone and has various potential applications such as soil improvement, removal of heavy metals and so on.