  We investigate the one-loop entanglement entropy of two short intervals with
small cross ratio $x$ on a complex plane in two-dimensional conformal field
theory (CFT) using operator product expansion of twist operators. We focus on
the one-loop entanglement entropy instead of the general order $n$ R\'enyi
entropy, and this makes the calculation much easier. We consider the
contributions of stress tensor to order $x^{10}$, contributions of $W_3$
operator to order $x^{12}$, and contributions of $W_4$ operator to order
$x^{14}$. The CFT results agree with the ones in gravity.
