A study of the site percolation model on the square lattice in a L×M geometry at critically is presented. For L≪M one observes the growth of numerous percolation colation clusters in the L-direction in contrast to the absence of percolation in the M-direction. Consequently, relevant properties of these clusters such us for example the average number of clusters (NCL), the cluster length distribution (P(l,L), with l=cluster length in the M direction) and average cluster length (lCL), are studied by means of the Monte Carlo technique and analyzed on the basis of finite-size scaling arguments. The following behavior is found:NCL≅(3/8) (L/M)−δ, with δ=1; andlCL≅2.0L. Also the distribution P(l, L) is of the exponential-exponential type and their characteristic exponents are evaluated.Instituto de Investigaciones Fisicoquímicas Teóricas y Aplicadas