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In the present paper, a new method called two-dimensional continuous-wave electron spin resonance (2-D CW-ESR) correlation spectroscopy is introduced. This method is based on mathematical analysis of ESR data obtained from common CW-ESR spectra. It is different from conventional 2-D ESR, which is built on multiple-pulse sequences. Synchronous and asynchronous 2-D CW-ESR correlation spectra defined by two independent magnetic field variable axes are generated by a correlation analysis of dynamic fluctuations of ESR signals induced by an external perturbation. The basic property of 2-D ESR correlation spectra is described. Several examples are investigated and discussed on applications of 2-D ESR correlation spectra in the spin self-trapping of 2-methyl-2-nitrosopropane (MNP), the mixture of spin adducts generated by self-trapping of MNP and 5,5-dimethyl-1-pyrroline N-oxide, and the coordination reaction of benzo-15-crown-5 with cupric ion in boron trifluoride-ether solution. The potential applications of this new 2-D CW-ESR method are discussed.