The (Al1-xGax)(0.5)In0.5P/InAs system has a large band discontinuity and is expected to improve the characteristic temperature of QD lasers by embedding InAs-QD in GaInP. We investigated the QD density and size of InAs-QD deposited on GaInP with various growth conditions, namely InAs growth temperature (T-s = 450-500degreesC) and As-flux (3 x 10(-7) -6 x 10(-6) mbar) by AFM measurement, and we compared the temperature characteristics of. InAs-QD embedded in GaInP with InGaAs-QW in GaInP, InGaAs-QW in GaAs and InAs-QD in GaAs by PL measurement at 10-380 K. The size and total volume of InAs-QD on GaInP increased according to the rise in growth temperature and As-flux, although the amount of deposited InAs was constant. This means that a considerable amount of In was supplied for the QD layer from the GaInP matrix and this was enhanced by the growth temperture and As-flux. Comparing the integrated PL intensity with GaAs/InAs-QD, it was shown that no obvious decline of PL intensity of GaInP/InAs-QD was observed up to around 200 K, though in GaAs/InAs-QD, it began to fall from around 50 K. Moreover, even when comparing with GaAs/InGaAs-QW, the integrated intensity of GaInP/InAs-QD became superior to that of GaAs/InGaAs-QW above room temperature. This result demonstrates that embedding InAs-QD in the GaInP matrix is considerably effective in improving the temperature characteristic of InAs-QD. (C) 2003 Elsevier Science B.V. All rights reserved.