The Remotely Operated Vehicle (ROV) Kaiko, built in 1995, is able to dive at ocean depths of 11,000m. On May 29, 2003, the Kaiko's secondary cable snapped, and the Kaiko's vehicle has been missing. JAMSTEC (Japan Agency for Marine-Earth Science and Technology) was decided to remodel the 7,000m class ROV UROV7K instead of the lost vehicle in order to continue the scientific activities. This system was called "KAIKO7000" system, and remodeling was finished in March 2004. After success of the sea trials, actual science activities that were interrupted by the Kaiko's vehicle lost was resumed in May 2005. JAMSTEC planed that over 10,000m deep segment sampling in the Challenger Deep at the Mariana Trench by using the launcher system of "Kaiko". On December 10, 2006, we are carried out the sea trial for the segment sampling in the Challenger Deep at the Mariana Trench by using the launcher system of Kaiko. The launcher reached the depth of 10,131m of the sea bottom at the Challenger Deep, and the core sampler "Asyura" succeeded in segment sampling. This paper describes about the method of deep-sea sediment sampling and the sea trial in the Challenger Deep at the Mariana Trench by using the launcher system of Kaiko.