I arrived at the United State on 17 Dec. My visa status is H1B. My posistion in the US is a postdoctor in a university. I came from China. According to the US-China tac treaty, Could I claim exemption for 2008?

In the U.S.-China tax treaty, there is no special treatment for one year for H-1B visa holders. What or which exemption are you enquiring about?

China DOES have a tax treaty exemption of $5,000, but that is for students and visiting researchers.

The H-1B visa is a work visa, so the treaty exemption will not apply.

However, you will file as a non-resident alien for 2007, and your $3,400 personal exemption will probably exceed the income you earned in the 15 days in 2007 that you worked.

In 2008, you will file as a resident alien just like the average U.S. citizen.