Taiwan’s decline in fertility is studied by using period parity progression ratios. Levels of marriage and motherhood are found to have been high and essentially constant though the late 1980s, suggesting that the decline has been due almost entirely to declines in second and higher order-births. Families with three or more children play an important role in maintaining the current level of fertility. The level of fertility would be even lower without these families. They contributed more than one-half child per woman to the total fertility rate during most of the 1980s. Total fertility rates computed from the period parity progression ratios indicate a substantially higher level of fertility than the conventional total fertility rate; they remained above or at replacement level through 1988. A formal demographic analysis suggests that the conventional total fertility rate has been depressed by shifts in age at childbearing.