Heat shock protein 90 (HSP90) widely mediated stress signal transduction, and plays an important role in the control of normal growth of human cells and in the promoting tumor cell development. At present, HSP90 has become forefront projects of cellular immunity, signal transduction and anti-cancer investigation. The physiological function of HSP90 start later in plant than in animal and fungi. Recent researches revealed that plant HSP90 plays an important role in development, environmental stress response and disease resistance. This paper discussed the molecular functions of HSP90, and systematically reviews latest progresses on molecular mechanism of plant HSP90 as well as improvement of plant resistance to facalitate broaden work.