Prices of rare earth metals and shares of related Chinese companies have been on a bull run in China on the eve of the introduction of a key resources tax expected in April.

Since the beginning of this year, average prices of 17 elements that are vital ingredients in high-tech products have doubled in China from the end of 2010 as speculative funds are now suspected of targeting the industry for huge returns.

Rare earths, a collection of 17 elements, are important ingredients in manufacturing sophisticated products, including flat-screen monitors, electric car batteries, wind turbines, missiles and aerospace alloys. However, mining the metals is very damaging to the environment.

As the world's largest rare earths producer and exporter, China adopted a series of policies for the industry this year to balance environmental protection needs and industrial demands, including stricter emission limits on miners, cuts in export quota and a resources tax.

China supplies more than 90 percent of the global rare earth demand. However, its reserves account for about one-third of the world's total.

Photo Luminescent Film, the main raw material of which is rare earth, also has to face to the price flucation this time. As the manufacturer of this film, we will increase the price globally from July.