This article aims to study the change in the selection of auspicious personal names in Thai society by comparing the first names of people of two age groups, over 81 years old and number 20 years old, at different periods of time : before 1921 and 1981-2000. The result of the study show that the first names of the young generation reflect a stronger belief in auspicious letters as practiced in the traditional naming textbook ?Tamrataksa? than those of the older generations. There are a few differences in the selection of names with favorable meanings of the old and young generations due to changing values.