This paper reconstructs the history of technological development of semiconductor in Samsung using previous studies, official company history, reminiscences, news materials, and so on. In 1982, Samsung made a large-scale investment in the advanced semiconductor business choosing DRAM as a major product. Samsung developed 64K DRAM in 1983 based on overseas training, and 256K DRAM in 1984 from technological introduction and in-house development simultaneously. Samsung developed 1M DRAM in 1986 and 4M DRAM in 1988 utilizing competition between domestic team and local subsidiary team. Samsung quickly participated in technological main current choosing C-MOS in 1M DRAM and stack type in 4M DRAM. Samsung developed 16M DRAM almost simultaneously with other leading companies in 1990, and 64M, 256M, 1G DRAM for the first time in the world after 1992. Especially, Samsung began to develop two generation products concurrently, and apply next-generation technology to present product. After the middle of the 1990s Samsung led the development of high-performance DRAM, and became world top enterprise in flash memory from 2003. Recently, Samsung expanded the investment to non-memory products, and new semiconductor market through fusion memory and multi-chip package. Samsung’s technological success in semiconductor was due to various factors including top management’s leadership, appropriate choice of technological paths, and exploitation of concurrent development systems.