The purpose of this research is to investigate the changes in countries of origin and occupational groups of immigrants to the United States after the implementation of the 1965 Immigration Act. The basic policy change in the 1965 Immigration Act was essentially the abolition of the National Origins Quota System. The new law led to obvious changes in the origins of immigrants. The number of Southern European, Asian and Caribbean immigrants significantly increased since the implementation of the Act. The sources of the various occupational groups shifted to some extent. The number of immigrants in the professional and highly skilled categories increased significantly. The impact of the changes aggravated the "brain drain" problem.