Solar studies are a long tradition of our Institute. However, today the research is conducted with a new emphasis. For the last fourteen years the institute's most outstanding achievments were the investigations on helioseismology within the scope of the IRIS - International Research on the Interior of the Sun Project. The Kumbel IRIS instrument started in Uzbekistan in 1988 became the first permanently operated station of the IRIS network. In May, 2000 IRIS instrument was replaced from Kumbel and installed in new pavilion at Parkent (Uzbekistan) and Helioseismic Laboratory was opened in Institute Material Science in Parkent. First observations of the new station took place at the end of May 2000.

Since the summer of 1996, the Institute has been involved in the Taiwan Oscillation Network (TON) project aiming at measuring high-spatial-resolution solar intensity oscillations to study the solar interior. The TON telescope is operating in Tashkent. The TON data can provide the information of modes up to l=1000. Because of the information on the wide range of degree, the TON data can be used to study many helioseismology problems, including the global and local properties of the Sun. Recently the data taken with the TON istrument in Tashkent were used to construct three-dimensional intensity and phase maps of the solar interior.