我查到的

http://uscis.gov/graphics/howdoi/h1b.htm#must

Must an H-1B alien be working at all times?

As long as the employer/employee relationship exists, an H-1B alien is still in status. An H-1B alien may work in full or part-time employment and remain in status. An H-1B alien may also be on vacation, sick/maternity/paternity leave, on strike, or otherwise inactive without affecting his or her status.