Objective To investigate the expression of heme oxygenase-1 (HO-1) by high glucose treatment in human lung epithelial A549 cells. Methods The effect of high glucose on the expression of HO-1 in A549 cells was investigated with Western blot and reverse transcription PCR. HO-1 enzymic activity and reactive oxygen species (ROS) production were investigated with enzyme-linked immunosorbent test. Results Treatment with 25 mmol/L high glucose for 0, 24 h, 48 h, 72 h and in concentrations of 5 mmol/L, 10 mmol/L, 25 mmol/L, 40 mmol/L for 48 h induced increased expression on protein and mRNA level of HO-1 in a concentration- and time-dependent manner in A549 cells. High glucose treatment increased production of ROS and transforming growth factor-β1 (TGF-β1) in A549 cells, which thus mediated HO-1 expression. Following the increase in HO-1 expression, the enzymatic activity of HO-1 also increased in high glucose-treated cells. Pretreatment with N-acetyl-L-cysteine (NAC) and PI3K/Akt inhibitors attenuated the high glucose-induced increased HO-1 expression. Conclusions High glucose increases ROS and TGF-β1 production in A549 cells, which mediates HO-1 expression and increases HO-1 enzymic activity.