The families of many upperclassmen on scholarships will probably be expected to contribute an additional $50 to $100 towards tuition next year.

Henry P. Briggs, Jr., director of freshman scholarships, said yesterday that the Financial Aid Office had studied the recent reduction in Federal income taxes, and would probably decide next month to ask parents to cover part of Harvard's $240 tuition increase.

The effects of the tax cut, he said, did not influence the size of scholarships given incoming freshmen because rate tables were not available when those determinations were made.

The total of scholarship aid given to the Class of '68 by the College will be between 22 and 33 per cent higher than the figure for the class of '67, according to Briggs. Exact figures cannot be computed until the College knows which and how many students will be coming here next year.

Twenty-five to thirty more scholarships were given to the class of '68 than to the Class of '67. The average size of each scholarship also rose, from $1200 to $1400.

The 375 or 380 freshmen who will hold scholarships next year will account for between $550,000 and $570,000, compared to $425,000 to $450,000 this year, Briggs said. The number of "admit-denies"--students who were accepted without being given the financial aid they requested--stayed approximately constant at 100.

Although several Ivy League schools, including Yale, have announced that they will not admit a student without giving him aid, Briggs said that the College did not want to drop its policy of keeping scholarship and admissions procedures independent.

Harvard's policy differs from Radcliffe's the admissions office has said that it rejected an unusually large number of girls this year because the financial aid they needed was not available.