The present study was carried out at four different experimental stations in the campus of Kyushu University and the immediate vicinity in Fukuoka from 1972 to 1973, to construct the life tables for an armored scale, Aonidiella taxus. The results are summarized as follows: 1. The nymphs of the 1st generation were deposited beneath the female scale covering in mid May. They developed to the reproducing stage in late July, and these newly developed mother scales continued nymph-deposition until late November. The nymphs of the 2nd generation being deposited in August developed to the reproducing stage in autumn of the year. Although they interrupted to deposit nymphs in winter with low temperature, they began to deposit nymphs again in the next May. On the other hand, the nymphs which were deposited in September, did not develop to the reproducing stage within the year. The nymphdeposition was postponed till the next May. 2. The total mortality from settling of crawlers to reproducing stage was considerably fluctuated between places or generations. Within crowns of Podocarpus macrophylla, a natural host plant of the scale insect, it ranged between 79. 0 and 93. 8 %, whereas within that of Liquidamber formosana which is not a host plant of this scale, it was extremely low, i. e., 4. 6 % in the 1st generation and 44. 0 % in the 2nd generation. 3. The mortality factors in the pre-producing adult stage was suggested as the key factor for population changes by the analysis of the Varley-Gradwell method. Parasites such as Comperiella bifaciata, Aphytis sp. and Prospaltella sp. B were dominant mortality factors in this stage.