Nylon filaments are manufactured by melt-spinning process such as UDY-DT (undrawn yarn-draw twist), POY (partially oriented yarn) and FDY (fully drawn yarn). In this study, dyeing properties of nylon filaments according to spinning process were investigated. The fact that microstructure of nylon filaments in amorphous region particularly is transformed by each spinning process was confirmed indirectly by measurement of dyeing rate because dyeing rate was affected by the structure of amorphous region. Diffusion rate of dye was fastest in POY not being drawn separately because drawing filaments increase amorphous orientation and disturb dye diffusion into amorphous region. Diffusion rate of dye was slower in UDY-DT having ${alpha}$-form crystal than in FDY having ${gamma}$-form crystal. But difference in K/S value, build-up and fastness was insignificant.