To balance the country's gender ratio, China should impose harsher punishments for medical workers who conduct illegal sex determination tests, a deputy to the country's top legislature said Tuesday.

Census data showed that China's gender ratio stood at 118.06 newborn boys for every 100 baby girls in 2010, which translates to roughly 1 million more boys born every year than girls, according to Yang Yunyan, a deputy to National People's Congress, the top legislature.

"Most of the surplus boys are born in rural areas, a fact that will greatly affect social harmony," said Yang, who is also the director of the Population and Family Planning Commission of central China's Hubei province.

The gender ratio imbalance has existed since the 1990s. Although authorities have made efforts to address the imbalance in recent years, it remains a serious problem, Yang said, blaming the imbalance partly on the insufficient enforcement of existing laws.

Although the laws are on the books, it is difficult in practice to punish certified medical workers who conduct illegal gender tests, he said.

Yang called on the Supreme People's Court to crack down harder on illegal testing cases, release relevant legal interpretations and consider heavier punishments for people who conduct illegal gender tests.

Yang cited a South Korean law that imposes a fine of 10 million Korean won (about 8,900 U.S. dollars) and a jail term of three years for illegal gender testing, stressing the importance of legal deterrents in solving the gender imbalance.