By the combined use of electron paramagnetic resonance (EPR) and transient absorption measurements, photophysical properties of tetra-tert-butylphthalocyaninatosilicon (SiPc) covalently linked to two 2,2,5,5-tetramethyl-l-pyrrolidinyloxy (PROXYL) radicals (R2a) have been investigated in terms of the photocontrol of magnetic properties. The steady-state EPR spectrum of R2a indicates that two PROXYL radicals generate a spin-correlated radical pair, where the singlet ground state (S-o') is close to the triplet ground state (T-o'). In time-resolved EPR (TREPR) spectra of R2a, A/E A/E A/E polarizations are initially seen, which then change into E/A E/A E/A polarizations. The initial and later polarizations are reproduced by spin-selective population of the So' and To' states, respectively. Quantitative analyses of TREPR and transient absorption signals show that the initial A/E A/E A/E polarizations are reproduced by spin-selective relaxation from the excited states, where the SiPc moiety is in the excited singlet state, and that the later E/A E/A E/A polarizations originate from the decay from excited multiplet states consisting of two doublet PROXYLs and SiPc in the excited triplet state.