The Function Points Analysis (FPA) of A.J. Albrecht is a method to determine the functional size of software products. The International Function Point Users Group, (IFPUG), establishes the FPA like a standard in the software functional size measurement. The IFPUG [3] [4] method follows the Albrecht's method and incorporates in its succesive versions modifications to the rules and hints with the intention of improving it [7]. The required documentation level to apply the method is the functional specification which corresponds to level I in the Rudolph's clasification [8]. This documentation is avalaible with some difficulty for those companies which are dedicated to develop software for third parties when they have to prepare the appropiate budget for this development. Then, we face the need of developing an early method [6] [9] for measuring the functional size of a software product that we will name to abbreviate it Early Method or EFPM (Early Function Point Method). The required documentation to apply the EFPM would be the User Requirements or some analogous documentations. This is a part of a research work now in process in Oviedo University. In this article we only show the following, results: From the measurements of a set of projects using the IFPUG method v. 4.1 we obtain the linear correlation coefficients between the total number of Function Points for each project and the counters of the ILFs number, ILFs+EIFs number and EIs+EOs+EQs number. Using the preliminary results we compute the regression functions. This results we will allow us to determine the factors to be considered in the development of EFPM and to estimate the function points.