To promote next-generation breeding of pine wood nematode-resistance for Pinus densiflora, it is necessary to consider the criteria for selection of crossing parents from many first-generation clones and to evaluate inheritance of pine wood nematoderesistance. We examined inheritance for nine sets of 4×4 half-diallele lines constructed using 36 pine wood nematode-resistant clones of P. densiflora as parents. Survival tree rates of the lines after pine wood nematode-inoculation varied greatly among six experimental sites and repeats within the sites, but also among lines at each site. Narrow-sense heritability was somewhat low, suggesting influences of site or location in the nursery. However, almost all genetic variation was explained by general combining ability. General combining ability estimated for the parent clones based on the REML method had a significantly positive relationship with the published resistance ranking of the parents based on their open-pollinated progeny. These results indicated that, by crossing between clones of high resistance ranking, it is possible to effectively develop more highly resistant, next-generation P. densiflora clones. The present study should provide fundamental information to ongoing programs for resistance breeding in P. densiflora.