你是用的winavr吗 是的话 在安装目录下 找头文件 例如mega128找到D:\Program Files\avr\include\avr\iom128.h
里面就有
/* Interrupt vectors */
/* External Interrupt Request 0 */
#define INT0_vect _VECTOR(1)
#define SIG_INTERRUPT0 _VECTOR(1)
/* External Interrupt Request 1 */
#define INT1_vect _VECTOR(2)
#define SIG_INTERRUPT1 _VECTOR(2)
/* External Interrupt Request 2 */
#define INT2_vect _VECTOR(3)
#define SIG_INTERRUPT2 _VECTOR(3)
/* External Interrupt Request 3 */
#define INT3_vect _VECTOR(4)
#define SIG_INTERRUPT3 _VECTOR(4)
/* External Interrupt Request 4 */
#define INT4_vect _VECTOR(5)
#define SIG_INTERRUPT4 _VECTOR(5)
..........