Prime Minister Yasuhiro Nakasone, apparently determined to use his bold style of leadership to improve badly strained ties with the United States, arrives Monday for his first official visit to Washington.

The thorny issues of trade and defense are likely to be the major points of contention when Nakasone meets President Reagan Tuesday for the first time since becoming prime minister on Nov. 26. During the White House talks, Nakasone is not expected to make any specific new pledges in the economic or military spheres.

In preparation for his visit, however, the 64-year-old leader has moved quickly on a broad front to address a number of long-standing U.S. demands. In so doing, he has attempted to cast himself as a man of action, who, unlike his predecessors, will not shrink from an enlarged global role for Japan more in line with the country's vast economic strength.

On Friday, Nakasone's seven-week-old Cabinet decided to approve the transfer of military technology to the United States, breaking with Japan's 15-year-old policy virtually banning the export of weapons. The day before, the Cabinet unveiled a package of 78 tariff cuts and plans to dismantle other import barriers--including curbs on foreign tobacco sales--that American businessmen complain bar them from the lucrative Japanese market.

Earlier in the week, Nakasone traveled to Seoul for talks with South Korean President Chun Doo Hwan, opening the way for a thaw in relations between America's key allies in northeastern Asia by offering the Chun government $4 billion in economic aid. On Dec. 29, Nakasone won approval for a 6.5 percent increase in Japan's 1983 military spending by overriding bureaucratic subordinates set on holding the line against Tokyo's massive budget deficits.

Taken separately, Tokyo's trade concessions and its defense decision fall far short of expectations of Reagan administration officials, who have demanded more drastic action in light of Japan's booming trade surpluses and the heavy U.S. military burdens in the Pacific. They are not likely to appease critics on Capitol Hill and among American business and labor leaders calling for protectionist sanctions against Japanese goods.

By acting swiftly on Tokyo's diplomatic backlog, however, Nakasone appears eager to create the impression that he intends to vigorously guide the country's powerful senior bureaucrats to early decisions on key issues. Nakasone's straightforward speaking style, and his flair for strong personal initiative, contrasts sharply with the verbally oblique manner of previous Japanese leaders, who have preferred to run the government by committee and avoid sharp public debate on national policy.

Since coming to office, Nakasone repeatedly has stressed the need to strengthen ties with the United States by providing a clearer statement of the direction of Japanese policy, something U.S. officials complain has been lacking in the past.

Western diplomats and political analysts here say that it is too early to tell whether Nakasone will be any more successful than his predecessors in breaking through the cautious, consensus-oriented approach in dealing with Washington.

But, as they see it, he has made a strong start, although not without churning up a storm of political opposition at home.

In opening the way for the first full-scale flow of Japan's sophisticated weapons-related technology to the United States, Nakasone abruptly ended a tortuous, 19-month-old debate among rival government departments over the wisdom of pulling the plug on the country's technological secrets. The decision came at the strong urging of U.S. officials, who had charged that Japan's refusal to reciprocate for U.S. arms technology was a sign of the country's unwillingess to pull its weight in two-way defense ties.

In announcing the move, officials here said it was made to ensure the effective future operation of the 32-year-old security treaty between Japan and the United States. They stressed it was an exception to Tokyo's overall policy prohibiting arms exports, which would remain in effect. Although the United States had expressed interest in acquiring advanced Japanese laser technology, fiber optics and industrial robots, the officials said the decision was not likely to result in actual exports any time soon.

The apparent policy shift brought a heated reaction from opposition parties in the Diet, or parliament. The Socialists, leaders among the country's vocal pacifist lobby, branded it "the worst case of imprudence in the postwar period" and threatened to hold up business in the 1983 Diet session, which begins later this month, unless the government reversed its stand.

In the area of trade, the most explosive part of relations between Japan and the United States, Nakasone's recent initiatives have met with a heated response at home. Tokyo announced Jan. 13 that it would substantially reduce import duties on 47 farm goods and on a lesser number of industrial products and would ease curbs on quotas for another half dozen agricultural items. While appearing minuscule to American officials, the moves have particularly outraged Japan's politically powerful farmers' lobby.

The United States, which had a record $20 billion deficit on trade with Japan last year, has been pressing Japan to do away with restrictions on the import of American beef and citrus fruit. The demands have been the centerpiece of the Reagan administration's negotiating efforts to open Japan's markets to more U.S. goods.

Nakasone is expected to tell Reagan that settlement of the issue any time soon is out of the question. On Wednesday, 10,000 Japanese farmers staged a protest outside the U.S. Embassy in Tokyo before presenting Nakasone with 9 million signatures on petitions opposing any further steps toward liberalization.

Foreign Minister Shintaro Abe, who will accompany Nakasone to Washington, said in a newspaper interview here today that to "strengthen the alliance between the two countries, it is quite important for Japan to tell the U.S. clearly what it can do and cannot do."

Reflecting the Japanese leader's confidence in his statesman-like qualities, Nakasone is expected to stress his broad, ambitious goals for Tokyo's diplomacy as a staunch U.S. ally. He embarked on those efforts during his visit to South Korea last week where he appeared to demonstrate Japan's determination to expand its role as a stabilizing factor in regional affairs.

In political talks with President Chun, the first between a Japanese leader and his South Korean counterpart, Nakasone pledged $4 billion in economic aid for Seoul's development programs in line with earlier statements that he intends to strengthen three-way ties among Japan, South Korea and the United States as key members of the free world.

The move fits the pattern of his apparent design to bolster Japan's defense ties with the United States to counter a growing Soviet military presence in the Pacific and use economic aid as a tool to help offset some of the heavy American commitments for security in Asia. Nakasone has stressed that Japan's constitution, which renounces war as an instrument of national policy, prevents Tokyo from undertaking a broader regional military role.

Nakasone, who speaks conversational English, told reporters here recently he expects to establish a "personal relationship of trust" with Reagan in talks Tuesday.

Other Japanese prime ministers have chosen to avoid such personal flourishes and have looked on summits in Washington chiefly as a ceremonial format for minimizing differences between the two countries in hazy words.

Nakasone is expected to offer his own strong views on the Soviet menace and the situation in the Middle East and express his ideas for what he has called a "new international order based on equality and mutual benefit."