The scale as a diagnostic tool plays an important role in discriminating between addicts and normal subjects. At the beginning of this chapter, we will briefly introduce the development of substance and non-substance addiction scales, which not only include alcohol addiction, nicotine addiction, cannabis addiction, pathological gambling pathological Internet use, but also exercise addiction, sex addiction, and food addiction, which are in dispute. While we will find almost all the addiction scales contain the items on social impairment, preoccupied, withdrawal, and tolerance, the variability is more pronounced with the non-substance addiction scales than the substance addiction scales. The comparison and the trends of the addiction scales in the future will be discussed on the concept of addiction, the development of assessment theory, the cross-cultural applicability, cross-sample applicability, and the positive side of addiction.