  Let $L$ be a Lie algebra of Block type over $\C$ with basis
$\{L_{\alpha,i}\,|\,\alpha,i\in\Z\}$ and brackets
$[L_{\alpha,i},L_{\beta,j}]=(\beta(i+1)-\alpha(j+1))L_{\alpha+\beta,i+j}$. In
this paper, we shall construct a formal distribution Lie algebra of $L$. Then
we decide its conformal algebra $B$ with $\C[\partial]$-basis
$\{L_\alpha(w)\,|\,\alpha\in\Z\}$ and $\lambda$-brackets $[L_\alpha(w)_\lambda
L_\beta(w)]=(\alpha\partial+(\alpha+\beta)\lambda)L_{\alpha+\beta}(w)$.
Finally, we give a classification of free intermediate series $B$-modules.
