This study considers patterns of participation according to gender in post-mass higher education from the perspective of higher education expansion in Taiwan. Becker's "D" coefficient ("D") is used to detect the patterns of gender parity in a 'critical mass' field in higher education. The study compared participation in STEM and the humanities in terms of gender parity. ARIMA was used to build the best-fit model to project the future trends of "D" in both programs. The findings suggest that more females are entering higher education and that there are little gender differences in those entering STEM programs. The gender gaps shown by "D" in the humanities and in STEM are narrowing rapidly in both the elite and mass stage, but the gap in the universal stage shows little change. The findings provide patterns of gender parity in different programs to interpret the effect of higher education expansion.