There is considerable economic incentive to convert methane into formaldehyde, which is used in the manufacture of insulating materials and adhesives. This paper discusses the kinetics of a one-step oxidation of methane with molecular oxygen over a MoO//3-SiO//2 catalyst. The space velocity was varied between 2,500 and 10,000 h** minus **1 (at NTP) over a range of temperatures from 848 to 92 K. Selectivities to formaldehyde between 30 and 89% were observed in the 0-5% methane conversion range, the other principal products being CO, CO//2, and H//2O. Kinetic analysis indicates that methane is directly oxidized to CO//2 and HCHO, with HCHO being further oxidized to CO.