In order to examine the dispersion stability of disperse dyes, the relationship between dispersion stability and conductivity in solution was investigated. Conductance ratios (C. R.) calculated from the conductivity of dispersing agents and disperse dyes were used for the estimation of dispersion stability. Generally, disperse dyes could form a stable dispersion through size reduction and narrow distribution of particles. The dispersion stablility and the dyeability of disperse dyes were improved by increased interaction between dispersing agents and disperse dyes. The interaction between disperse dyes and dispersing agents was expressed using C. R. The dispersion stability was evaluated and compared with the dyeability. Also, the particle size analysis was employed. The relationship between C. R. and the dispersion stability was confirmed. It is supposed that C. R. has potential as a method for the evaluation of the dispersion stability of disperse dyebath.