X-ray measurements on samples of Al-Pd-(Fe,Ru,Os) systems with various annealing temperatures and times have been performed in order to gain insights into formations of icosahedral (I) phases and related approximants and to produce single phases of them. As a result, well ordered I phases have been obtained in Al-Pd-(Ru,Os) systems when annealed at 1000 °C for several hours. Formations of the (1/0-1/0-1/0) and the (2/1-2/1-2/1) approximants have been observed in wide compositional ranges in Al-Pd-(Fe,Ru,Os) and Al-Pd-(Ru,Os) systems, respectively. Electrical resistivity measurements of I phases and related approximants are performed as a function of temperature. The resistivity of I phases at room temperature is as high as that of highly resistive I phases such as Al-Pd-Mn and AI-Cu-(Fe,Ru) systems and the resistivity ratio (P12K/P300K) reaches about 1.5 in Al-Pd-Ru I phases. A negative temperature coefficient of the resistivity is observed in (1/0-1/0-1/0) approximants of Al-Pd-(Fe,Ru) systems, which indicates the electronic transport is quite anomalous even in the lowest approximant of the I phase.