PARIS (AP) _ Ample lines and soft fabrics dominated the runways Wednesday in early shows for next winter's ready-to-wear fashions. A busy week of shows will be held in tents in the Tuileries Gardens and other locations throughout Paris.

The 1,500 journalists and 700 buyers from all over the world viewing fashions will have to pick and choose, since there will be over 40 shows and not enough time to see them all.

Paris is expected to trot out a huge array of clothes, from long skirts and hooded duffel coats to neat suits as Givenchy previewed them - a trim red spencer over sleek black and white checked skirt.

There may be less gimmickry and craziness than past seasons, since fashion houses realize it costs money to parade clothes that nobody will actually buy and wear.

Several Japanese designers have jumped the gun in early shows, with varying results. Hiroko Koshino opted for mounds of wrapped broadcloth and some leather and jerseys, with a strong look in dresses with big hip drapes, all very Japanese in feeling.

Koshino's big runway number was a huge, fan-like stiffened net hairpiece, more for effect than for serious fashion.

The color palette here is subdued, with lots of black, dark blue, slate and anthracite. The silhouette is a voluminous triangle or somewhat tubular shape.

Yuki Torii, another Japanese who has exhibited in Paris for several seasons, went in another direction, concentrating on hot-colored knitwear.

The ski and apres-ski clothes here are fetching, including northwoods and abstract jacquard patterns on big sweaters and cat-suits. The active ski outfits in black nylon look original with big rhinestone decor on high turtle necks.

Forget the too-wild tricolor tight knit dresses, but the short knit pastel bolero cardigans with big flowers could liven up the chalet scene.

Meanwhile, a new house called Pia Lorenti gave a show on a barge docked on the Seine. Edith Cresson, Minister of Trade and Industry, was on hand for the debut of this enterprise, which manufactures in Chatellerault, near Tours and Poitiers - where Madame Cresson is mayor.

The Italian-sounding name apparently has nothing to do with this collection, designed by Frederic Hildebrand, a Swiss designer who has worked with Ungaro. The house is definitely an all-French company, and hopes to market in the United States by 1986.

The clothes are ample, and in soft fabrics, featuring paisley-lined coats and jackets, glossy wool chemise dresses and intriguing silk tops with pink or turquoise swirl patterns over wrapped silk jersey skirts.

The Pia Lorenti show had some echoes of Norwegian designer Per Spook, who's been successful in Paris for some years now. This was not exactly an accident. The key promoters of Pia Lorenti once worked for Spook.

His low-keyed show in his shop off the Champs-Elysees was a success for lovers of sporty lines. Never boring, Spook carefully edits his shows down to ''tableaux'' of several outfits ranging from day into evening.

This season, he's opting as usual for lots of long looks in soft flannels, with wraparound skirts, or loose pants slightly nipped at the ankle. His use of prune, midnight blue and purple in an outfit of separates is striking, and his long leather coats with contrasting flannel linings could be a wardrobe classic.

But those who love color will go for the combinations of milk chocolate brown and hot tomato red in one outfit, or even a total siren red look in several pieces.

He uses soft lurex fabrics very well, especially in blousing tops, and his wide gold lam trenchcoat could be a must for those who can afford it. He dresses women who like to travel, and the critics approved of his white, red or violet fitted evening dresses in crinkled parachute silk - with contrasting shawls unfolding from little bags like parachutes, but not recommended for jumping.

Other early glimpses showed short skirts at Chanel, Ricci and Laroche, and perhaps Saint Laurent will have a rigorously tailored line with fantasy for evening.