  The aim of the present paper is to apply the Laguerre polynomials method for
the analytical solution of the Altarelli- Martinelli equation. We use this
method of the low $x$ gluon distribution to the longitudinal structure function
using MRST partons as input. Having checked that this model gives a good
description of the data to predict of the longitudinal structure function at
leading and next to leading order analysis at low $x$
