Omar Abdullah, 38, is the disputed state´s youngest ever chief minister. [break]
His party won most seats in recent polls but fell short of an overall majority and struck a deal with the Congress party to form a government.
India controlled Kashmir saw months of protests against Indian rule in 2008 and Abdullah faces many problems.
The elections were held in phases amid tight security. Kashmiri separatists called for a boycott.
Monday´s oath-taking ceremony in the state´s winter capital, Jammu, was attended by Congress party President Sonia Gandhi.
The National Conference, the largest pro-Indian party in Indian-administered Kashmir, won 28 seats in the 87-member state assembly - still well short of a majority.
Congress, which leads the government in Delhi, won 17 seats. The two parties are equally represented in the cabinet of 10.
Accepting the oath of office, Abdullah promised to uphold the sovereignty and integrity of India.
Related story
Omar Abdullah comes out in support of Zaira Wasim
