The paper investigates the real interpolation spaces concerning the entropy spaces (studied by C. P. Calderón and R. Fefferman) and block spaces (studied by Y. Meyer, M. H. Taibleson, G. Weiss). Two of such interpolation spaces are characterized in the paper by the explicit calculation of the \(E\)-functional. These two kinds of spaces are \[ (L^\infty, L^0_{\text{ent}} )^{1/p}_{p,1;E} = L^p_{\text{ent}}, \qquad 1\leq p0, \;0 t\})\), \(E\) is the entropy, and \(B\) is the space generated by \(\infty\)-blocks, \(\Lambda_f (s)= \inf\{ \sum_k \varphi (s|\theta_k|)\}\), \(\theta_k\)'s are disjoint intervals s.t. \(\{|f|> s\}\subset \bigcup_k \theta_k\). Some applications of the results are also discussed.