The Reagan tax-cut package, approved in its final form by Congressional conferees on Saturday, may hurt Harvard efforts to raise funds from individual contributors and large corporations. University officials and several economists said yesterday.

Major provisions in the bill, including the reduction of the maximum personal income tax rate, will make it less attractive for private supporters to donate money or stock to Harvard, by increasing the net "cost" of such contributions.

"A Chilling Effect"

The Reagan package could have "a very chilling effect," as one University official put it, especially when combined with the substantial cuts Congress has approved for federally sponsored campus research and student loans.

Parker L. Coddington, director of government relations for Harvard, said that despite the potential adverse effects of the tax cuts and spending reductions. Harvard officials must now cling to "one chief hope that the administration program does achieve its ends" in cutting inflation, increasing the Gross National Product, "and building a generally stronger economy, so that there will be money to give to places like Harvard."

Even as they cross their fingers for the administration's plan, however, Harvard financial officers will focus attention on serious shortfalls caused by budget cuts in agencies like the National Science Foundation, Coddington said. "If we can make a case to private contributors that we have been hurt in enough areas, perhaps we can encourage support in spite of the tax problems," he added.

The University recently passed the midway point in a five-year, $250-million capital fund drive aimed largely at contributors who will be affected by the tax cuts.

Problematic Provisions

Two of the provisions of the tax bill that could discourage private contributions to universities like Harvard are:

* The reduction of the maximum individual tax rate from 70 per cent to 50 per cent. A person in the highest tax bracket now keeps only 30 cents out of every dollar he earns, so if he gives a dollar to Harvard--a non-taxable contribution--he "loses" only that 30 cents.

With the tax cut, the same person will keep 50 cents for every dollar earned, thus the "cost" of giving a dollar to Harvard rises from 30 cents to 50 cents. "Studies indicate that charitable givers are very sensitive to the tax price, or cost, of giving, and the changes should have fairly important results for universities." Alan J. Auerbach, assistant professor of Economics and an expert on tax policy, said.

* The reduction of the maximum rate on long-term capital gains taxes from 28 per cent to 20 per cent. If a person buys $1000 in stock that subsequently doubles in value, he may decide to donate the stock to Harvard to avoid paying a capital gains tax and to allow himself a further tax deduction for charitable giving. Under the existing law, the donation of the $2000 in stock "costs" only $320.

With cuts in the capital gains and personal income levies, the same contribution will "cost" $800, and the general price of giving stock to Harvard will rise from 16 cents on the dollar to 40 cents on the dollar.

Lawrence B. Lindsey, an associate of Auerbach's at the National Bureau of Economic Research (NBER) and an instructor for the summer version of Economics 10, called the capital gains reductions "particularly dramatic in regard to universities" and estimated that as much as 40 per cent of Harvard's income from private contributions could evaporate.

Less Drastic Predictions