We have investigated InAs quantum dots (QDs) on strained GaAsSb barrier layer in different Sb compositions. Use of Sb incorporated barrier layer for QD growth gives better quantum dot properties such as density, lateral size and uniformity. Growing GaAs0.89Sb0.11 results in a doubling of QD density and a 50% decrease in size of the QDs compared to growth on GaAs. Also, size distribution of QDs became narrower after incorporating Sb. These are described based on atomic force microscope (AFM) and its analysis data. X-ray Diffraction (XRD) shows Sb composition as a function of Sb/As flux ratio. On the basis of Reflective High Energy Electron Diffraction (RHEED) oscillation surface morphology of GaAs1-xSbx is described as well.