President Carter said yesterday he will propose "substantial tax reductions" next year and may delay submission of some controversial tax revision recommendations until Congress enacts the tax cuts.

In a nationally televised news conference, the President made clear that his first objective next year will be enactment of the tax cuts to spur the economy rather than revisions or "reforms" of the nation's complex tax laws, which during his campaign he described as "a disgrace to the human race."

Some of the more controversial items on tax reform that have been proposed to me - they would be very time-consuming and have very little monetary significance - might be delayed until later on, because I feel that it is necessary to expedite the effectiveness of substantial tax reduction," he said, adding, "I am committed and the Democratic congressional leaders at least are committed to substantial tax reduction in 1978 as soon as we can put it through."

Carter did not specify which tax revision proposals he is considering delaying, but they could include such controversial plans as ending the special tax treatment given to capital gains.

Nor did the President indicate the size of the tax cut he will recommend. However, he reiterated that the tax reductions would be aimed at offsetting the higher Social Security taxes and higher energy prices that would result from passage of administration bills pending in Congress.

The higher Social Security taxes and energy prices are expected to total $36 billion between now and 1981. In a speech about two weeks ago, Commence Secretary, Juanita M. Kreps said a $15 billion tax cut will be necessary next year just to keep pace with an already expected increase in Social Security taxes, higher energy prices and the effects of inflation.

The higher Social Security taxes Carter is seeking would take effect after next year.

Speaking of the pending energy legislation which remains bogged down in a House Senate conference committee, the President sought to assure congressional supporters of his energy plan that he will not abandon them. But Carter also indicated he expects to play a largely passive role in the weaving together of the House passed legislation, which contains most of his original proposals, and the weaker Senate passed bill.

Some of the President's supporters in Congress have worried about that the administration may yield in the end to the demands of the oil industry and one of its chief spokesmen, Senate Finance Committee Chairman Russell B. Long (D-La.). Seeking to lay those fears to rest, Carter said yesterday:

"We will add our assistance when we can, but we will not betray the confidence of people who look to us for leadership and I will not work out any private agreement with Senator Long that would betray the commitment that we have made previously, publicy, I might say, in all instances."

At the same time, the President refused to say whether he would accept energy legislation setting the price of natural gas at more that $1.75 per thousand cubic feet, the price he proposed last April. He said he will maintain his original position on natural gas pricing "as long as possible." But, in effect, Carter told the House conferees that it is up to them to negotiate a compromise with Long and his supporters, leaving him to judge whether to sign into law what the negotiations produce.

On other domestic topics during the news conference, which was dominated by questions about the Middle East, the President:

Announced that the federal government will soon undertake a four year, $67.5 million program to inspect 9,000 "high-risk" dams across the country. In the process, Carter said, federal officials will train state inspectors who eventually will take over the program.

Said he has not decided whether to reappoint Arthur F. Burns as chairman of the Federal Reserve Board when his term as chairman expries next month. But, in contrast to the words of a praise he had for Burns at his last news conference, Carter said, "I don't believe anybody is indispensable, you know, a president, or tha chairman of the Federal Reserve Board or anybody else."

Described as "quite disturbing" the United States' record $3.1 billion trade deficit last month, which he blamed on two factors - "our extraordinary importation of foreign oil," and the fact that an improving U.S. economy has spurred the purchase of goods from overseas.

Although Carter did not hint what "reforms" his tax proposal next year may include, sources confirmed yesterday they are almost certain to be only a shadow of the compreshensive tax-revision program originally planned last September.

A special White House Treasury tax group has recommended a pared back version that would eliminate the centerpiece of the earlier program - the provision to the end the special tax treatment of capital gains.

The administration also tentatively has scrapped a proposal designed to reduce the so-called "double taxation" of corporate earnings, first as profits and then as stockholder dividends.

The President specifically said in the 1976 campaign that he would seek to end the present preferential tax treatment of capital gains and the double taxation of corporate dividends.

The treasury would gain several billion dollars a year if capital gains were taxed at the same rates as ordinary income. It was thus hard to know exactly what the President meant yesterday when he said the "reforms" he was delaying would have little "monetary" significance.

The major "reforms" expected to remain include the conversion of the $750 personal exemption to a tax credit, the reduction of the so-called "marriage penalty" and new restrictions on the "Martini" business-lunch deduction.

Carter met Tuesday with a group that included Treasury Secretary W. Michael Blumenthal and Stuart H. Eizenstat, his domestic affairs adviser, in a 1/2 hour session to go over the recommendations.

Sources said Blumenthal urged Carter to adopt a "simple" package based primarily on the tax cuts the President hopes to propose. Eizenstat is said to favor a somewhat more expanded package.

The President indicated yesterday that those "reform" proposals left our of the first tax bill would be submitted later, but tax reform groups say this probably means these prososals could not be enacted in this 95th Congress.