After returning to Indonesia, he worked at a bank between 1934 and 1940 while also teaching law part-time. During the
Japanese occupation period, he worked under the Mangkunegaran. Near the end of the war, he was assigned to Jakarta to head an economic office. He had also been a member of the
Central Indonesian National Committee, while not being part of any political parties. He was appointed as a member of the 15-man Working Committee within the body. He was mostly active in academia and education, being appointed as chairman of the "Indonesian Congress of Education" upon its founding in 1947, and cofounding the Institute of Indonesian Culture in 1948. He also took part in the founding of the Indonesian Police Academy in 1946, for a time serving as its chairman. He became a professor of sociology at the
University of Indonesia by 1949, becoming one of its first Indonesian professors. In 1950, when the faculty of economics was established there, Sunarjo was appointed as its first dean, due to a shortage of economists. At the request of
Mohammad Roem, he also helped found the Political Science Academy (
Akademi Ilmu Politik) in
Yogyakarta (today part of
Gadjah Mada University). Kolopaking died on the evening of 31 March 1972 and his body was interred at the Menteng Pulo Public Cemetery the next day. ==References==