Provided is a binder for a secondary battery including a copolymer including repeating units of the Chemical Formula 1, Chemical Formula 2, Chemical Formula 3, and Chemical Formula 4 disclosed herein. When the binder for a secondary battery is applied to a negative electrode and a secondary battery, expansion of the negative electrode may be effectively suppressed. Furthermore, the binder for a secondary battery has improved adhesion to effectively suppress exfoliation and desorption of a negative electrode, thereby manufacturing a secondary battery having significantly improved charge/discharge cycle characteristics and battery performance by using the binder.