Electrical and magnetic properties of (Ca(1-x)A(x))(2)MnO4 (A=La and Na) have been studied. When a certain amount of La is doped to the Ca site, i.e., electrons are doped, antiferromagnetically ordered magnetic moments are canted and show spontaneous magnetization below 115 K. Electrical conduction is dominated by thermally activated electrons above 115 K, and by hopping electrons below 115 K. The Na doped or hole doped samples (Ca,Na)(2)MnO4 also exhibit spontaneous magnetization below 115 K. The electrical conduction mechanism in (Ca,Na)(2)MnO4 is the same as that in (Ca,La)(2)MnO4. However, when a low magnetic field (<30 Oe) is applied to a (Ca,Na)(2)MnO4 sample, the magnetic susceptibility becomes negative below 40 K.