Three strategically located countries in the Indian Ocean area have proved receptive to the idea of letting American forces use their ports and airfields in a crisis, Pentagon spokesman Thomas B. Ross said yesterday.

Administration hopes for obtaining access to bases in Kenya in East Africa, Somalia on the Horn of Africa, and Oman on the Arabian Sea have been buoyed to the point that the Pentagon soon will send a team of specialists to the three countries to assess their potential for handling American warships and aircraft.

Encouraged by the reception a team of State Department and Pentagon officials received in a pre-christmas swing through the three countries and Saudi Arabia, the Carter administration is following up with an inventory of available facilities in Kenya, Somalia and Oman. The depths of channels, lengths of airport runways and sites for storing U.S. military equipment will be surveyed, defense sources said.

Making measurements and refining them into a report for policymakers is expected to take two months. Sources said the idea is to prepare the way for a decision by late February or early March on the use of bases in the Indian Ocean theater.

Ports and airfields on the Horn of Africa and in the Persian Gulf area are seem as crucial to America's ability to use military power in those distant potential trouble spots.

Although Ross did not go into it at his briefing yesterday, sources said that Kenya was especially receptive to an American military presence there and in neighboring Somalia.

During a meeting with U.S. officials Dec. 21, Kenyan leaders said they viewed an increased Anerican military presence as a stabilizing influences in East Africa. One Kenyan leader went so far as to say that the United States was welcome to use any of Kenya's ports.

The administration's plan for Kenya calls for sending ships into its ports on a regular basis, using Kenyan airfields, storing a limited amount of military equipment there, and sending a small team of Navy specialists on a permanent basis to coordinate the use of Kenya's ports.

Kenyan leaders, sources said, told the visiting Americans that a U.S. naval presence in Somalia might have a restraining influence on that country. Kenya and Somalia have been at odds in the past.

Although letting the U.S. Navy use the facilities the Soviets build in the Somalian port of Berbera in inviting, one high-ranking U.S. official warned yesterday that this might draw protests, possibly gunfire, from neighboring Ethiopia.

Despite such potential perils, the administration shows every sign of steaming full-speed-ahead in its search for launching pads for U.S. military power along the Horn of Africa and in the Persian Gulf area.

The search for bases is being conducted at two levels. One is the hurryup effort to find existing ports to use in an emergency -- with Kenya, Somalia and Oman the prime candidates.A parallel, more long-ranged effort is tied to the Rapid Deployment Force that President Carter is organizing.

The Joint Chiefs of Staff are surveying ports and airfields in the Indian Ocean area that the Rapid Deployment Force, expecteded to be ready for action in 1982, could use. The search, however is still a paper exercise, as contrasted with the recent on-the-scene conversations involving the Pentagon-State team.

Along with looking for places to land U.S. forces, the administration is moving ahead with plans to build cargo planes and ships to help extend the reach of American power the 12,000 miles from the United States to the Persian Gulf. A new version of the C5 cargo plane, called the CX, and a fleet of cargo ships are part of this quick-reaction preparation.

The planes would be able to fly nonstop, thanks to aerial refueling, from the United States to distant trouble spots. The planes would carry cargo and troops, but would be designed primarily for heavy equipment such as tanks.

The cargo ships to back up the Rapid Deployment Force would be stationed near likely trouble spots. The idea is to keep the troops in ammunition, food and other supplies once they land.

The administration is downplaying its interest in Saudi bases because the Saudis currently do not welcome an American military presence.

Although the Kenya port of Mombasa and the Somalian naval facilities at Berbera could accommodate some U.S. warships, admirals warn that giant aircraft carriers would still have to anchor offshore at either place.

Another problem from the long-term standpoint is a lack of facilities on the Horn of Africa and the Persian Gulf to a accommodate sailors on liberty or their families, if the U.S. government eventually establishes some type of permanent presence.