The contents of chemical components such as total nitrogen, total amino acid and vitamin C were somewhat higher in $N_2$ gas treatment at $10^{circ}C$ for 3 hours than those of other treatments. However, the contents of tannin and chlorophyll were slightly lower than that in the other treatments. The content of ${gamma}-Aminobutyric$ acid with $N_2$ gas treatment was higher $1.5{sim}6$ times with values of $51{sim}205mg/100g$ than in control (35mg/100g). The scores of sensory test was not different between $N_2$ gas treatment for 3 hours and control. The contents of chemical components such as total nitrogen, total amino acid including theanine and caffeine were slightly higher in $N_2$ gas treatment at $20^{circ}C$ for 3 hours than those of other treatments. However, the contents of tannin and vitamin C were slightly lower than those of other treatment. The content of GABA in tea leaves treated with $N_2$ gas was higher $2.5{sim}7$ times with values of $85{sim}225mg/100g$ than in control (35mg/100g). The sensory test was lower in $N_2$ gas treatment($76.3{sim}78.1$ point) than in control(80.4 point). The contents of chemical components were not different between $N_2$ gas treatment at $30^{circ}C$ for 3 hours and control. Whereas the contents of chemical components were somewhat lower in $N_2$ gas treatment for 1 hour and 5 hours than in control. The content of GABA in tea leaves treated with $N_2$ gas was higher $3{sim}7$ times with values of $115{sim}217mg/100g $than in control(35mg/100g). The sensory test was lower in $N_2$ gas treatment ($74.3{sim}78.4$ point) than in control(80.4 point). Consequently, tea mading within 5 time $N_2$ gas treatment at $10^{circ}C$ or 3 time $N_2$ gas treatment at 20, $30^{circ}C$ after plucking was considered to be the best green tea in terms of functional nature as well as taste nature.