Anode-supported tubular solid oxide fuel cells and 4-cell-stack with lanthanum-doped ceria barrier layer and strontium, magnesium doped lanthanum gallate tri-layer electrolytes membrane are investigated. The single cell exhibits peak power densities of 1061 mW cm(-2) and 917 mW cm(-2) at 800 degrees C fueled with bubbled hydrogen and methane (3 vol % water), respectively. Energy dispersive X-ray detector result demonstrates that no measurable carbon is detected in the anode directly operated in methane during the whole testing process. The 4-cell-stack assembled with single cells provides maximum output power of 1.66 W and open circuit voltage of 3.13 Vat 800 degrees C with hydrogen as fuel. While the 4-cell-stack presents maximum output power of 1.38 W and open circuit voltage of 3.88 V at 800 degrees C fueled with methane. A stability test of each cell in 4-cell-stack is developed at constant current densities (J = 0 A cm(-2), J = 0.1 A cm(-2), J = 0.4 A cm(-2)) directly fueled with 75 ml min(-1) methane at 800 degrees C. The results show that the voltages of each cell in 4-cell-stack stabilize during the whole durability test. The results demonstrate that the stability and dependability of 4-cell-stack is good, and it is promising for mobile application of intermediate temperature solid oxide fuel cells.