InGaAs/GaAs quantum well (QW) and quantum dot (QD) structures grown on GaAs (111)B substrates under different growing temperatures are investigated by magneto-photoluminescence (PL) up to 15 T in both Faraday and Voigt configurations. The spatial extents of the carrier wave functions (ECWFs) are deduced from the diamagnetic shift of the PL peak energy. The binding energies of the InGaAs/GaAs QWs are evaluated to be about 5 meV. The QW ECWFs in the growth direction obtained by the diamagnetic shift are consistent with those calculated by the k · p theory. The heights and radii of the InGaAs/GaAs QDs are also estimated from the ECWFs. In addition, we found that the in-plane ECWFs decreased slightly as the growth temperature was varied from 525 to 450°C. The ECWFs in the growth direction decreased when the growth temperature was varied from 525 to 480°C and then increased as the temperature was decreased to 450°C.