The catalytic properties of gold have been widely investigated. In Dr. Chao-Ming Chiang¡¦s study, department of chemistry of NSYSU, they found that the organic molecules, propanal, form heterocyclic 2, 4, 6- triethyl-1, 3, 5-trioxane ring on Au(110) missing row surface at 180 K by temperature programmed desorption (TPD) and reflection absorption infrared spectra (RAIR). In this study, we used low energy electron diffraction (LEED) and scanning tunneling microscopy (STM) to study the detailed catalytic process on surface. Residual gas analyzer (RGA) was used to measure the thermal desorption of the propanal on Au(110) at 130 K and 185 K. This can be used to calibrate the temperature on the surface, which can not be directly measured by the thermal couple on the manipulator. The combination between the LEED pattern from the experiment and the DFT model shows the propanal adsorbed on the inclined plane with about 64 deg. to 71 deg. companing the (110) plane. The STM results also show that some of the surface after adsorption have trench wider atomic rows. In our experiment, the real temperature of the sample was not exactly determined. More experiments need to be taken to confirm the temperature.