Experimental results obtained for the implantation into MBE grown AlGaAs/GaAs heterostructures are reported in this paper. The electrical activation of implanted Si atoms takes place at an annealing temerature as low as 625°C in GaAs. In AlGaAs, it requires temperatures higher than 700°C, probably due to a higher density of defects remaining there than in GaAs. It is also clearly shown by Shubnikov-de Haas measurement that two-dimensional electron gas (2DEG) accumulates at the interface of low-dose Al implanted AlGaAs/GaAs heterostructure after annealing at 700°C, which indicates that implantation doping can be applied to AlGaAs/GaAs heterostructure for practical use while maintaining the essentiaal transport properties of 2DEG at the interface.