The move follows a call by China early in December for southwestern neighbour India to avoid complicating a simmering dispute over a visit by a senior exiled Tibetan religious leader to a border region.
The two countries fought a brief border war in 1962.
Beijing views exiled Tibetan spiritual leader the Dalai Lama as a dangerous separatist. The Nobel Peace Prize winner, who says he simply wants genuine autonomy for his homeland, fled to India in 1959 after a failed uprising against the Chinese.
Sunday's change "provides a legal foundation to combat potential terrorist activities brought by the further opening-up of Tibet," the paper quoted Wang Chunhuan, a scholar of the Tibetan Academy of Social Science, who worked on the new law, as saying.
The measure brings land ports and trade zones within the scope of the previous law, and charges low-level government with the responsibility of tipping off police to help regulate the border, according to the article, published late on Monday.
"The need to combat separatism, infiltration, illegal migration and terrorism is growing more severe by the day," as Tibet's economy opens to the world, Ba Zhu, deputy head of the region's border defence police, said in a Dec. 14 announcement, the official Tibet Legal Newspaper reported at the time.
Army troops in Tibet had built a "steel Great Wall" to defend the border, the Himalayan region's Communist Party chief, Wu Yingjie, said in a December speech published on the official China Tibetan News Agency website on Tuesday.
Wu also quoted President Xi Jinping as saying, "To govern the nation, we must govern our borders; to govern our borders, we must first stabilize Tibet."
Military capability in the region must be stiffened so as to "absolutely not allow any person, at any time, in any way, to separate out any part of Tibet," Wu urged.
(Reporting by Christian Shepherd; Editing by Clarence Fernandez)
(This story has not been edited by NDTV staff and is auto-generated from a syndicated feed.)