I'm assuming you mean overall strategy. The Japanese wanted to defend their home islands. To do this they built a "ring" of defenses by capturing key specific islands in the Pacific from which they could stop any incoming attacks. This also helped them ensure that they could ship raw materials from their new territories in the East Indies and Malaya.

The Americans on the other hand, started off very slowly and didn't do much but defend their few holdings in the pacific. They fought Japan on the sea, but the Americans considered Germany the first priority and thus ground operations weren't really being done on a large scale early on in the war. However, the Americans eventually adopted an island hopping strategy to break down the Japanese ring of defense. The Army and Navy argued over this, with the Navy saying that they should bypass most of the islands and go straight for islands like Taiwan. The army won that debate after MacArthur appealed to the president directly.

As Japan's defenses fell, they changed their strategy, and they began to focus on causing as many casualties as possible in hopes of turning the American public against the war. This is when the Japanese started using Kamikazes in great numbers and they began to fight tooth and nail for every square inch of land.

Sources:

The Pacific War: 1941-1945: John Costello

The Pacific War: From Pearl Harbor to Hiroshima: Daniel Marston

Japan's Imperial Army,Its Rise and Fall by Edward Drea.