Generally speaking,the intron size positively correlates with recombination rate in Caenorhabditis elegans genome.Here,we analyze the correlations between recombination rate and some measures of different intron lengths so as to know whether the recombination influences the introns of different lengths in the same way.Results show that the correlation between the recombination rate and the percentage of short introns(＜100 bp)is negative,but the correlation between the recombination rate and the percentage of introns that are larger than 500 bp is positive.Average intron length correlates positively with the recombination rate for introns whose length is in the range of 100-1000 bp.We speculate that the recombination mainly exerts impact on introns whose length ranges from 100-1000 bp.We also show that the average intron number per gene correlates negatively with the recombination rate.