The inclusive decays of 𝐵-mesons to charmonium have been studied in a data sample of 386 million $B\bar{B}$ events. The data sample has been collected by the Belle detector at the KEKB asymmetric energy 𝑒⁺𝑒⁻ collider operating at the $\Upsilon (4S)$ resonance. The branching fractions have been measured for the inclusive decays to $J/\psi + X$ and $\chi_{c1} +X$. The measured branching fraction for $J/\psi + X$ is $\mathcal{B}(B \rightarrow J/\psi (\rightarrow e^{+}e^{−}) + X) = (1.10 \pm 0.005 \pm 0.057)\%$ and $\mathcal{B}(B \rightarrow J/\psi (\rightarrow \mu^{+}\mu^{−})+X) = (1.08 \pm 0.004 \pm 0.056)\%$, while the inclusive $\chi_{c1} +X$ branching fraction is found to be $\mathcal{B}(B \rightarrow \chi_{c1} + X) = (0.44 \pm 0.01 \pm 0.06)\%$. The feed-down contribution from higher charmonium states is subtracted from the measured branching fractions and the direct branching fractions are obtained to be $\mathcal{B}(B \rightarrow J/\psi +X) = (0.77\pm 0.04 \pm 0.06)\%$ and $\mathcal{B}(B \rightarrow \chi_{c1} +X) =(0.41 \pm 0.01 \pm 0.06)\%$.