The use of lattice girder is increased rapidly as a substitute for H-steel ribs at the tunnel sites in Korea. Ground loads acting on the tunnel are supported by shotcrete and lattice girders. To assess the safety of the tunnel, it is essential to obtain field measurements for the lattice girders; however, lattice girder measurements have rarely been performed at tunnel sites, and the method of measurement is not well established. In the present study we suggest a load cell method for the instrumentation of tunnels with lattice girders. Actual measurements of ground loads acting on lattice girders are presented for a specific tunnel under construction.