In this paper, the hydrothermal conversion of glucose to lactic acid (LA) using sodium silicate (Na2SiO3) as a mild base catalyst was investigated. The results showed that Na2SiO3 was effective catalyst for the conversion of glucose. The highest LA yield of about 30% was obtained from glucose with a lower concentration of Na2SiO3 at 300 degrees C for 60 s. It was also found that the use of Na2SiO3 led to a much less corrosion and a higher LA yield than that with NaOH at the same pH value. This process provides an environmentally friendly and highly effective method toward the synthesis of useful LA from glucose. (C) 2015 Elsevier B.V. All rights reserved.