  The purpose of this paper is to study the limiting distribution of special
{\it additive functionals} on random planar maps, namely the number of
occurrences of a given {\it pattern}. The main result is a central limit
theorem for these pattern counts in the case of pattern with a simple boundary.
The proof relies on a combination of analytic and combinatorial methods
together with a moment method due to Gao and Wormald~\cite{GaoWormald}. It is
an important issue to handle the overlap structure of two pattern which is the
main difficulty in the proof.
