The two women were abducted in Malaysia's eastern state of Sabah, known for its natural attractions such as world-class scuba diving, but also for recurring kidnappings blamed on bandits from the Muslim southern Philippines.
Gao Huayuan, 29, a tourist from Shanghai, was taken along with Filipina hotel employee Marcy Dayawan, 40, in a raid by about six gunmen at around 10.30pm (9.30pm Thai time) Wednesday, Malaysian media reports said.
The raid occurred at the Singamata Reef Resort near the town of Semporna on Borneo island. The women were reportedly taken away in a boat.
Malaysia Prime Minister Najib Razak said the attack could be an attempt to stir up more trouble between China and Malaysia. He did not elaborate.
"Our priority is to ensure the safety of the hostages," he was quoted as saying by Malaysian state-run news agency Bernama.
Mr Najib spoke in Perth while visiting the Australian staging base for the massive search for the missing Malaysia Airlines flight, the majority of whose passengers were Chinese.
It was not known who the kidnappers were or where the victims were taken. Bandits have in the past abducted tourists and others in the area and taken them to nearby Philippine islands.
But China urged Malaysian police to rescue its citizen and improve safety.
"We sent relevant staff to the site and ask the local police to make an all-out rescue effort while ensuring the security of Chinese citizens and taking effective measures to safeguard the security of Chinese tourists," Foreign Ministry spokesman Hong Lei told reporters.
He said China would "follow this incident closely".
Malaysian police and resort staff have declined comment.
The incident is another blow for the image of Sabah, and for Malaysian tourism, in MH370's wake.
More than 200 armed Islamic guerillas from the Philippines staged a bizarre invasion of eastern Sabah last year, holding out for month until they were crushed by a Malaysian military assault. Dozens of people were killed.
Malaysia ratcheted up security afterwards and has repeatedly declared the area safe for visitors. But abductions and other incidents have continued.
Malaysian security forces searched nearby seas Thursday for the gunmen, reports said.
Philippine maritime police and other authorities were "actively and closely" coordinating with their Malaysian counterparts in hopes of a "speedy resolution of the case," the Philippine embassy in Kuala Lumpur said in a statement.
China's consulate on Borneo island on Thursday advised its nationals to "pay attention to personal safety" when travelling to Sabah and to avoid "remote islands".
Flight MH370 vanished March 8 with 239 people aboard, including 153 Chinese nationals, sparking heavy criticism of Malaysia by Chinese relatives, and pressure from Beijing.
Chinese state media have reported that fewer holiday-makers from China were booking Malaysian tours in the wake of MH370.
Chinese tourism has earned increasing revenue for Malaysia.
Some 1.8 million Chinese visited last year, a 15% annual increase, making China the third-biggest source of visitors to Malaysia.
Eastern Sabah has seen several kidnappings over the years.
In the biggest single case, armed Philippine gunmen took 21 hostages at the world-renowned diving island of Sipadan near Semporna in the year 2000, including 10 tourists from Europe and the Middle East. All were eventually released.