A death toll appraoching 1,500 Cubans killed in African combat has not shaken popular support in Cuba for President Fidel Castro's actions, U.S. intelligence officials said yesterday.

According to recent estimates, about 1,000 Cubans soldiers have been killed in the Angola civil war and some 500 in Ethiopia during that country's fight to oust Somalians from disputed territory, intelligence officials said.

As a rule of thumb, U.S. military authorities, who asked not to be identified, calculated that wounded generally outnumber killed by about a 3-to-1 margin.

One official acknowledge the figures were somewhat speculative because there is no reliable information on the actual number of Cuban soldiers wounded or missing in three years of African operations.

Intelligence officials estimate that there have been about 40,000 Cuban military men in Africa, many as combat troops in Angola and Ethiopia. Others are said to have been stationed in several countries as advisers and technicians. Troops are often replaced after a one-year tour of duty, they said.

The senior officials said Cuba's military involvement in Africa conflicts remains "extremely popular" at home. Other officials have said that only heavy casualties would be likely to cause the Castro regime political problems.

Opposition to the Cuban actions in Africa has been limited to complaints by friends and families of men sent to serve there, intelligence experts said, adding that there is no orgainized opposition.

Intelligence officials said they have no information to confirm some reports that Cuban wounded are being treated in Soviet and East European hospitals rather than being sent home, where they might arouse poipular concern about Cuban military involvoment in Africa.

One official said that some Cuban dead are returned to Cuba for burial but most are buried in Africa.