By progress of technology, it became possible for us to do many kinds of operations in virtual environment. However side effect is called simulator sickness may occur to human body when human come in contact with this new environment. It makes symptoms similar to motion sickness. Many studies about that were started in 1950s and have actively been progressing in other countries, but in Korea recognition about that field is insufficient. Main contribution of this paper would be the base study about phenomena of simulator sickness which may be occurs in simulator or virtual reality environment, factors which induce simulator sickness, and quantifying methods of simulator sickness.