Sudokwon landfill has installed manifold stations to collect LFG For the effective collection of LFG it is essential to understand the functions of manifold station containing manifold and branches and the changes of flow and pressure in manifold station. We monitored the changes of pressures, velocities and gas compositions of each branch by changing the opening of butterfly valves which is currently being used to control the volume. The LFG, collected through manifold station contains various ranges of air inflow in which oxygen is consumed to oxidate methane which increase the ratio of carbon dioxide to methane in LFG Each branch combined into manifold showed different pressures, velocities and gas compositions caused by the amount of LFG collected and the degree of air intrusion. Results showed that shortage of LFG caused the increase of suction pressure in branch.