The Maryland harness racing scene shifts to Laurel Raceway tonight for the first of 67 nights of racing and continues through Sept. 16.

Ten races are scheduled nightly with triple wagering on the first and 10th races and exacta betting on the other eight. Post time is 8 p.m.

The Laurel facility underwent a fine inspection Monday and was deemed fit to open. Previously 54 fire-hazard violations had been found, but only one remained on Monday. A state racing official said yesterday that flaw was minor and the track was given 30 days to correct it.

According to Cloverleaf, the horsemen's association, Laurel will have to average a $450,000 nightly handle in order to maintain the purse structure - $1,400 to $10,000 maximum for overnight races - Rosecroft introduced this spring.

Rosecroft averaged a record $497,515 (up 3 percent from $483,856) for its 67 nights. Laurel's 1977 average handle was $418,424. A major reason for the increase at Rosecroft was the inclusion of the first-race triple, which brought bettors to the track earlier.

It will be about two weeks before any trend on the handle will be established. A Laurel official said the track would like to apply additional purse money to lure big-name horses to the track. The track will open with a $1,400 minimum purse.

For the bettor, the only major difference at Laurel will be the size of the track - a five-eighths of a mile oval, that negates some of the value of inside post position and/or early speed that were so necessary at the half-mile Rosecroft track.

Track officials report that horsemen have filled Laurel's barns and that 90 percent of the standardbreds competing at the Howard County track will be coming over from Rosecroft. The other stables are shipping in from Freehold (N.J.) Raceway.

The only top Rosecroft driver missing from Laurel will be Bobby Myers, who had the highest percentage at Rosecroft in the Universal Driver Ratings. He is taking his stable to Brandywine (Wilmington, Del.). Wayne Smullin, the leading dash winner at Rosecroft, will compete at Laural.

The track will offer three stakes series - the Laurel, the Reading Futurity, and the Maryland Standardbred Fund - with total purses of more than $400,000.