* Iron ore imports surge 18 pct, copper 21 pct on month
* Stockpiling, holiday disruptions likely the cause, not demand
* Overall trade figures raise optimism about China's economy
BEIJING, Feb 12 (Reuters) - China's imports of crude oil, iron ore and copper hit record highs in January, though some of the unexpected strength was put down to stockpiling ahead of the Lunar New Year holidays rather than underlying strength in consumption.
At the same time, data showed the value of China's overall imports and exports climbed around 10 percent last month from a year ago and handily beat expectations, raising optimism over the health of the world's second-largest economy after recent weak data.
Some analysts, though, questioned whether the data may have been inflated by fake transactions, where traders forge deals so as to sneak cash into the country past capital controls.
Mark Keenan, head of commodities research in Asia at Societe Generale, said the data on commodities imports underpinned strength across the board at a time when the world was very focused on China after the recent emerging markets rout.
"If China retains an element of stability, it will calm sentiment toward the rest of the emerging markets," he added.
China's imports of iron ore surged to a record 86.84 million tonnes in January, defying expectations for a fall and rising more than 18 percent compared to the previous month, data from China's customs authority showed on Wednesday.
The figure was also a third higher than the same period of last year and exceeded the previous record set in November by 11.6 percent.
Analysts had expected shipments to China, the world's biggest iron ore consumer, to have fallen in January, with prices declining to a six-month low during the month amid growing uncertainty about demand in the country's steel sector.
The big increase is unlikely to have been driven by underlying demand from the country's massive steel sector, which has been struggling with weak demand, a lack of credit and a drive by Beijing to clean up the environment.
Copper imports also surged more than 50 percent in January from a year ago to a record high, as tight credit conditions late last year encouraged traders to hike shipments, and on restocking ahead of the Lunar New Year, traders said.
China imported 536,000 tonnes of anode, refined copper, alloy and semi-finished copper products in January, 21 percent higher than the 441,291-tonne total in December, customs data showed.
"The strength is very surprising - even accounting for seasonality and restocking ahead of the holidays," said Sijin Cheng, analyst at Barclays in Singapore.
"Financing demand was very, very strong," Cheng added.
Tight credit conditions in China's domestic market due to a cash crunch in November that stretched into December fanned import demand, Cheng added.
Importers of refined copper can sell their stocks on the domestic market to raise capital for more lucrative investments elsewhere, often in the real estate market.
China, the world's largest soy buyer, imported 5.91 million tonnes of soybeans in January, up 23.7 percent from a year ago, but down from a record 7.4 million tonnes in December.
China's crude oil imports in January rose 11.9 percent from a year earlier to a record 28.16 million tonnes, or 6.63 million barrels per day (bpd), according to the customs department.
Imports of refined oil products fell 3.8 percent from a year ago to 3.76 million tonnes, the customs department said. (Reporting by Judy Hua, David Stanway, Melanie Burton, Niu Shuping, Chen Aizhu and Jacob Gronholt-Pedersen; Writing by Ed Davies; Editing by Muralikumar Anantharaman)