Here we extend the research of the ͑R ,Ca͒MnO 3 perovskites to the smallest-R end member ͑Lu, Ca͒MnO 3 . Magnetic and magnetotransport properties of the ͑Lu 1−x Ca x ͒MnO 3 system are systematically investigated in regard to carrier doping. It is found that hole doping into the antiferromagnetic x = 0.0 phase, LuMnO 3 , causes a spin-glass-like magnetic competition in the wide doping range of 0.1Յ x Յ 0.6, whereas electron doping into the antiferromagnetic x = 1.0 phase, CaMnO 3 , induces a large magnetoresistance effect for 0.8Յ x Յ 0.95.