Spontaneous blinking as a function of visual activity and environmental condition with 60 healthy Korean young people(M=30, F=30) was estimated. Spontaneous blink rate of male and female was $19.2{pm}2.0/min$ and $18.7{pm}2.0/min$, respectively. There was no significant difference of blink rate in both contact lens wearer and non-wearer of female and also by various visual activity between female and male. Spontaneous blink rate was changed in response to changes in levels of visual activity and environmental condition such as windiness, rut not changed by light. In the more intense fixation spontaneous blink rate was lesser, but in the stronger windiness, the rate was higher than that in normal.