The law -- passed on the closing day of the NPC's annual session -- intends to safeguard the assets of China's growing middle class by reassuring them their property rights are secure and strengthening protection for private businesses, a sector that accounts for 65 percent of China's gross national product.
Supporters of the law claim it could help reduce disputes over property that have become the leading cause of social unrest in cities and the countryside when farmers are pushed off their land to make way for housing and factories, often with little or no compensation.
It is an extension of a clause inserted three years ago into China's constitution that says private property is "not to be encroached upon." Officially turning the statement into law faced opposition from many of China's lawmakers and intellectuals who believe it contradicts the basis of China's socialist principles.
In recent years, however, economic reforms have shifted in the communist country toward more open market, capitalistic policies as it tries to maintain the pace of its rapid development.
With these reforms, many left-wing members of the Communist Party have come to question the government's commitment to the country's poor. Allowing private property, the law's critics say, will encourage corruption and put more power in the hands of an elite few at the expense of the poor.
A petition with 3,200 signatories gathered by left-wing opponents of the law argued that it would increase the gap between China's rich and poor. It faulted the law for not distinguishing between property gained through hard work and property gained through corruption.
The Chinese government released a draft of the law in 2005, sparking a debate by leading intellectuals on both sides in media outlets and on Chinese Web sites. The controversial proposal was originally expected to be taken up last year, but officials withdrew it at the last minute. The latest draft of the law was not circulated and the Propaganda Department put a ban on reporting on more recent versions of the proposal.
China's Prime Minister Wen Jiabao, skirted addressing the law in his opening remarks of the National People's Congress and, along with President Hu Jianto, has avoided entering the property rights debate.
The law easily passed on the last day of the assembly's 12-day meeting with 2,799 votes in favor, 52 opposed and 37 abstaining.