Transoceanic flights over East China sea have been discussed since 1982 as a collaborative experiment between Japanese and Chinese scientists. This was realized in 1986 to perform test flights, launching balloons in Kyushu Inland. Two flights were conducted in July and those payloads were successfuley recovered near Shanghai area. This paper describes some details of launching, tracking, payload and recovery for these test flights. tions prepared by both Japanese and Chinese groups are scheduled in the summer of 1987.