In this research we have synthesis four disperse dyes and the yield of dye IA ~ dye IVA was obtained above 85%. It was found that the long chain alkyl group was introduced into the amino group of the monoazo dye to cause a large redshift effect, so the dye color changed from old rose to dark slate blue. All dyes were dyed on polyester fiber in supercritical carbon dioxide and the dyed sample were evaluated for ISO and AATCC standards such as washing color fastness, water color fastness, perspiration (acid, alkali) color fastness and rubbing color fastness. The study found that in supercritical carbon dioxide dyeing, dye IIA and IIIA has more than 85% dye relative up-take at first time dyeing. It is meaning dye IIA and IIIA suitable for dyeing in supercritical carbon dioxide on polyester fabric. The colorfastness result showed that, the laundering, water, perspiration fastness and rubbing fastness properties of the dyed samples were adapted to commercial requirements.