Abstract. The effect of neutrality on evolutionary search is known to be crucially dependent on the distribution of genotypes over pheno-types. Quantitatively characterizing robustness and evolvability in geno-type and phenotype spaces greatly helps to understand the influence of neutrality on Genetic Programming. Most existing robustness and evolv-ability studies focus on mutations with a lack of investigation of recombi-national operations. Here, we extend a previously proposed quantitative approach of measuring mutational robustness and evolvability in Linear GP. By considering a simple LGP system that has a compact representa-tion and enumerable genotype and phenotype spaces, we quantitatively characterize the robustness and evolvability of recombination at the phe-notypic level. In this simple yet representative LGP system, we show that recombinational properties are correlated with mutational proper-ties. Utilizing a population evolution experiment, we demonstrate that recombination significantly accelerates the evolutionary search process and particularly promotes robust phenotypes that innovative phenotypic explorations.