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In this study, various equivalence ratios and Reynolds numbers were used to investigate the thermo-acoustic instability in the impinging jet flame using syngas fuel. Various instability modes occurred in syngas of H2:CO=50:50 composition ratio, and this study focused on the description of the characteristic of each mode and tendency analysis. It was classified into 4 types of Regime by equivalence ratio and Reynolds number, that is, Regime II-1, II-2, II-3, and II-4 respectively. The shapes of the flame and the flow field in representative conditions of each regime were visualized, and the pressure fluctuation data were verified to be clearly different through various methods (FFT, phase portrait, recurrence plot). Also, there was a section in which the frequency and intensity of the noise decreased as the heat capacity(equivalent ratio or Reynolds number) increased, and it is another criterion for dividing the regime. Finally, the sensitivity was confirmed through the correlation between the two dominant frequencies (II-1, II-3) and Reynolds number, equivalence ratio.