Recently C. Bardos et al. presented in their fine paper \cite{Bardos} a proof of an Onsager type conjecture on renormalization property and the entropy conservation laws for the relativistic Vlasov-Maxwell system. Particularly, authors proved that if the distribution function \(u \in L^{\infty}(0,T;W^{\alpha,p}(\mathbb{R}^6))\) and the electromagnetic field \(E,B \in L^{\infty}(0,T;W^{\beta,q}(\mathbb{R}^3))\), with \(\alpha, \beta \in (0,1)\) such that \(\alpha\beta + \beta + 3\alpha - 1>0\) and \(1/p+1/q\le 1\), then the renormalization property and entropy conservation laws hold. To determine a complete proof of this work, in the present paper we improve their results under a weaker regularity assumptions for weak solution to the relativistic Vlasov-Maxwell equations. More precisely, we show that under the similar hypotheses, the renormalization property and entropy conservation laws for the weak solution to the relativistic Vlasov-Maxwell's system even hold for the end point case \(\alpha\beta + \beta + 3\alpha - 1 = 0\). Our proof is based on the better estimations on regularization operators.