Based on Kolmogorov’s equation of filtered quantities [1,2], a new dynamic subgrid model for magnetohydrodynamic (MHD) turbulence is obtained. Similar to Politano’s derivation [3], when the two-point distance ξ is much larger than the filter size, and is located in the inertial subrange, the simplified formulation of Kolmogorov’s equation for filtered quantities reads: 1 $$ - 4\varepsilon _f^T \xi /5 = A^T ,{\rm } - 4\varepsilon _f^C \xi /5 = A^C,$$ in which $$\varepsilon _f^T$$ and $$\varepsilon _f^C$$ are the total dissipation and cross dissipation, respectively. The terms on the right hand sides are $$A^T = \left\langle {\delta u_{_l }^{ < ^3 } (\xi )} \right\rangle - 6\left\langle {b_{_l }^{ < ^2 } (x)u_{_l }^ < (x + \xi )} \right\rangle ,A^C = - \left\langle {\delta b_{_l }^{ < ^3 } (\xi )} \right\rangle + 6\left\langle {u_{_l }^{ < ^2 } (x)b_{_l }^ < (x + \xi )} \right\rangle .$$