The far-Infrared [CII] 158μm line is the dominant coolant of neutral intersterllar gas. We made survey observations of the [CII] line with a dedicated system called BICE (Balloon-borne Infrared Carbon Explorer). We made two successful balloon campaigns : one to the United States, and the other to Australia. We observed various kinds of objects, including the Galactic plane (255°≲l≲78°, |b|≲3°), the Cygnus-X region, the ρ Ophiuchi dark cloud, and the Large Magellanic Cloud. The observational resulsts are briefly disccused.