Out of slimy, primitive origins, namely marine algae, may come a new treatment for inflammatory diseases and a chance for one Tukwila, Wash., company to do business in China.

Biomarine Technology Inc.'s product, and how it may come to be produced in an algae-growing and -extracting operation in a province near Shanghai, is an outgrowth of the research of Rodner Winget, a biochemist fascinated with the possibilities of algae, a primitive form of plant life that grows in abundance in both freshwater and marine environments.Mr. Winget, who holds a doctorate in biochemistry and has a string of post-doctorate fellowships and government grants on his resume, said his ''entire career has been directed toward developing marine resources, including food and drugs, from the sea."

Although there are 50,000 varieties of marine algae, Bioma- rine President Sandy Hoboy said researchers have found uses for only about 10 of them.

Mr. Winget became interested in a fatty acid contained in fish oil, popularly known as Omega-3. Eicosapentaenoic acid, or EPA, as scientists call it, has been linked to beneficial health effects, from lower rates of heart disease to treatment for burns and other inflammations.

Although the beneficial effects of fish oil are well-known, it has an unpleasant side effect - it stinks.

Either in topical applications or ingested, EPA makes the patient smell unpleasantly of fish.

"Even with fish oil capsules, you get a kind of fishy aftertaste," said Mr. Winget, adding that some people who take it orally complain that even their sweat smells like fish oil.

Mr. Winget eventually discovered that EPA could be extracted from marine algae.

He started his project by gathering seaweed and analyzing it for the presence of EPA, using facilities provided by the University of Washington biochemistry department. In 1988, he incorporated Biomarine Technologies.

The specific algae Biomarine uses to extract EPA is proprietary. Mr. Winget's research has been financed through grants from the National Institutes of Health, including the National Heart, Lung and Blood Institute; the National Institute of Arthritis; and the National Cancer Institute.

Commercial use of Bioma- rine's version of EPA, called DermEPA, in this country is a few years away. Mr. Winget sees the algae extract as an eventual alternative to corticosteroids, which prevent inflammation but can have side effects.

But in August, thanks to a trade fair put on by the Kent Chamber of Commerce, Bioma- rine attracted the attention of the Chinese.

Ms. Hoboy now has began discussions with the Xzhou Economic Development Zone in Jiangsu, a province north and east of Shanghai. The Chinese, who have used fish oil as a burn treatment for generations, were interested.

In China, Ms. Hoboy said, Biomarine would need 100 acres of growing area for the algae, which could be grown in converted rice paddies near a supply of saltwater. The processing plant could be built in any industrial area.

So the long dance of developing a relationship with Chinese partners has begun. Biomarine now is checking out potential business partners through contacts in Beijing, and is consulting with an engineering group in China to learn how to negotiate the Chinese system.