The richest one-fourth of American households - those with incomes of $17,000 a year or higher - took home half the income in this country in 1976 and paid more than 70 percent of all personal income taxes.

By contrast, those in the poorest one-fourth - wage earners making less than $5,000 a year - received less than 5 percent of the nation's income that year and paid a minuscule 0.1 percent or less of the income-tax tab.

Those in the richest 5 percent of the country - taxpayers with incomes of $30,000 or more - earned 22 percent of the income in 1976 and paid 39.2 percent of all income taxes.

By contrast, the poorest half of all persons filing tax returns earned 19 percent of all income and paid 6 percent of the personal income taxes in 1976, meaning the richer half paid 94 percent.

Those figures, complied by the Treasury Department from estimates based on 1976 income levels, show a stark fact about the way the tax burden is distributed in this country.

While it's true, as some studies show, that weathier persons enjoy the biggest tax breaks and deductions, they also shoulder a disproportionate share of the tax burden - far beyond what is perceived generally.

Moreover, the distortion has been heightened by the tendency of Congress in recent years to skew most of the tax breaks it's enacted to those at the lower end of the income scale.

To make up for inflation and higher Social Security payroll taxes, the lawmakers have cut income taxes. But most of the cuts have benefited lower and lower-middle-income taxpayers - not the middle or the top.

The result of all this his been a significant tax squeeze on the so-called "middle" and "upper-middle" income brackets - the 10.7 million taxpayers whose incomes fall between $20,000 and $35,000 a year.

While the proportion of Americans' personal income eaten up by the income tax has remained relatively constant over the past few years, at about(See TAXES, A4, Col.4) (TAXES, From A1) 13 percent, the burden of that tax load has shifted to higher-income brackets.

For example, figures compiled by the Tax Foundation show that the richest 25 percent of the nation's taxpayers paid 68.3 percent of all taxes in 1970. By 1975, that figure had risen to 72 percent.

Those in the richest 50 percent paid 89.7 percent of the total tax in 1970. By 1975, that had increased to richer 50 percent bracket saw their share of the total tax tab rise.

At the same time, those in the poorer half enjoyed a shrinking tax burden during the period. The taxes paid by the lower half fell from 10.3 percent in 1970 to 7.1 percent in 1975.

For the poorest 25 percent of all taxpayers, the proportion of the total from 0.9 percent in 1970. In any case, the trend is clear.

President Carter's new tax-cut package would only heighten the disparity. Carter has proposed replacing the present $750-a-dependent personal exemption with a new $240 credit that would shift the burden further toward the middle and upper-middle-income brackets.

The battle in Congress now is precisely over how far that shift should be allowed to go. Members of the House Ways and Means Committee have indicated that they are concerned about the tax burden borne by upper-income brackets and most likely will revampt the Carter proposals.

Moreover, the heavier tax burden continually is reaching downward to include people who used to be in lower-middle-income brackets. As inflation pushes income higher, taxpayers are thrust into higher brackets.

With the combination of inflation and higher tax rates in the upper brackets, the wealthiest of the nation's taxpayers pay disproportionately high shares of the total tax burden - even including their shelters and deductions.

For example, the richest 1.4 percent of the nation's citizens - some 985,000 whose incomes total $50,000 or more a year - take home 10.7 percent of the income, but pay 23 percent of the taxes.

The wealthiest 0.3 per cent - those in the $100,000-and-up category - receive 4.5 percent of the total income, but pay 10.5 percent of the tax burden. (The poorest 0.3 percent escape taxes altogether.)

The breakdown portrayed by these figures pertains only to personal income taxes. with Social Security payroll taxes included, the pattern is different but the point remains the same.

The figues used in the computations include income from capital gains - profits from the sale of stocks or other assets - only half of which are subject to tax. The totals for tax liability include writeoffs and deductions.

For all the complaining about wealthy taxpayers, those in the richest half of the nation's income brackets are paying 93.8 percent of the personal income taxes. The other half is paying the rest.