A Chinese delegation led by Vice President Xi Jinping is in Tibet for ceremonies marking 60 years of direct Chinese rule in the territory.
Others in the 59-member delegation include Vice Premier Hui Liangyu and Chen Bingde, the armed forces chief of staff.
China's official news media say the 59-member delegation was greeted at Lhasa's airport Sunday by about 600 residents in colorful festive clothing. The reports say the residents performed dances and honored the visitors with white ceremonial scarves.
Chinese media quoted residents saying their lives have been improved since what China calls the "peaceful liberation" of Tibet in 1951. However, officials imposed heightened security and strict controls on travel to the region, apparently fearing a repeat of anti-Chinese riots in Lhasa three years ago.
Asia News, a news service operated by the Catholic Church, quoted border officials in Nepal saying security at the crossing into China is the tightest they have ever seen. Travel agencies have also reported that tourism to Tibet has been halted until later this year.
In Lhasa Sunday, the visiting vice president cut a ribbon to open a new expressway, cutting travel time to the city's airport in half. Beijing says it has spent almost $50 billion on hundreds of development projects in Tibet since 1951.
China released a white paper last week stressing the economic benefits its rule has brought to Tibet and saying freedom of religious belief is guaranteed for all ethnic groups in Tibet.
That contrasts with the views of Tibetan exile groups, which say China uses discriminatory practices to suppress their form of Buddhism and their cultural traditions. They also say China has encouraged thousands of Han Chinese to migrate to the region, where they increasingly dominate the government and the economy.
Hundreds of people were arrested or disappeared after ethnic frustrations broke out in rioting in the Tibetan capital, Lhasa, three years ago. China still maintains a high security presence around a Tibetan monastery in Sichuan province where a young monk set himself on fire to protect Chinese policies in March.