With in the status attainment research framework, this study takes the effect of the background factors on the subjects' first job opportunity as the indicators of the job opportunity inequality. Using the national survey data provided by the research team on stratification of "The Basic Survey of Social Change in Taiwan, l992", it examines the changes in the occupational opportunity inequality in the process of economical development during the past 40 years as represented by the effect of place of birth, sex, father's occupation, father's education, and other background variables on the subjects' job opportunity; it also tests the hypotheses of the similar issues proposed by foreign researchers. The Conclusions are as follows: He overall influence of the background factors on the first job opportunity (R square) has dropped sharply in the process of economic development during the past 40 years indicating a sharp decline in the first job opportunity inequality. The causes are: 1.The wide spread of elementary and secondary education as demanded by the increasing economic development─people of all backgrounds can get an education─has decreased the educational opportunity inequality and thus causes the decline in the first job opportunity inequality accordingly. 2.Rural industrialization has increased job opportunities in both industrial and service sectors and thus reduces the rural-urban differences of the occupational opportunity by weakening the impact of the place of birth on the first job opportunity. 3.The influence of father's occupation on the first job opportunity has (after controlling for education) progressively declined.