We report the discovery of a multi-planetary system transiting M0 V dwarf HD 260655 (GJ 239, TOI-4599). The consists at least two planets, namely b, with period 2.77 d, radius R$_b$ = 1.240$\pm$0.023 R$_\oplus$, mass M$_b$ 2.14$\pm$0.34 M$_\oplus$, and bulk density $\rho_b$ 6.2$\pm$1.0 g cm$^{-3}$, c, 5.71 R$_c$ 1.533$^{+0.051}_{-0.046}$ M$_c$ 3.09$\pm$0.48 $\rho_c$ 4.7$^{+0.9}_{-0.8}$ cm$^{-3}...