Fruit firmness is considered as essential trait for tomato fruit quality and ranks as second important of the tomato evaluation index after fruits flavor. In this study, by using the introgression line （IL）population derived from S. pennellii LA0716, the firmness of tomato were measured in three part of the red mature fruits including fruit shoulder, mid-part and pedicel through puncture test. Our results indicated that there is a significant correlation among different parts of the fruits for the firmness. Based on the genetic map of the introgression line, five QTLs named qF-p-1, qF-p-2, qF-p-3, qF-p-4 and qF-p-11 for increasing the fruit firmness were located on Chromosome 1, 2, 3, 4 and 11 respectively. In addition, two QTLs（qS-p-4 and qS-p-10）for reducing the firmness of tomato fruit were located on Chromosome 4 and 12. Among these QTLs, qF-p-4 accounted for the highest firm variation and qS-p-10 accounted for the highest soft variation. Compared with the firmness QTLs that previously identified from other wild tomato species, we found that most of the QTLs were co-localized on the tomato chromosomes. It indicated that the tomato fruit texture might be a trait which was been selected during the domestication. Results obtained in this study will be of great benefit for fine mapping and cloning of the major QTLs which control the tomato fruit firmness, and a foundation for the firmness improvement in tomato breeding.