Purpose: The aim of this study was analyzed by comparing the effect of glass fiber reinforcement addition on the strength of resin denture base. It was intended to provide a reference data useful for clinical application. Methods: The test specimens (length $64.0{pm}0.1mm$, width $10.0{pm}0.1mm$, thickness $1.0{pm}0.1mm$, $1.5{pm}0.1mm$, and $2.0{pm}0.1mm$ respectively) were made. In the experimental groups resin denture base reinforced with glass fiber were fabricated. In the control groups resin denture base were fabricated by conventional method. After specimen fabrication was completed, transverse test was performed using a universal testing machine. Results: The transverse strength value in CON group was $83.08{pm}9.07MPa$ for 1.0 mm, which ranked the highest in value. On the other hand, the value was $56.07{pm}5.15MPa$ for 2.0mm, which ranked the lowest in value. And CON+SES group was $119.80{pm}30.70MPa$ for 1.0mm, which ranked the highest in value. On the other hand, the value was $84.00{pm}7.97MPa$ for 2.0mm, which ranked the lowest in value. Also, the flexural modulus value in CON group was $2,983.10{pm}506.92MPa$ for 1.0mm, which ranked the highest in value. On the other hand, the value was $1,257.64{pm}230.48MPa$ for 2.0mm, which ranked the lowest in value. And CON+SES group was $4,679.41{pm}1578.29MPa$ for 1.0mm, which ranked the highest in value. On the other hand, the value was $2,512.36{pm}527.09MPa$ for 2.0mm, which ranked the lowest in value. Conclusion: The reinforced glass fiber increased the strength of resin denture base, effected to reduce the thickness of resin denture base.