Barry equalled the all-time record during his side's goalless draw with West Ham United this afternoon, more than 19 years after making his debut for Aston Villa in May 1998.
The 36-year-old only joined West Brom from Everton this summer, but Pulis has been impressed by what he has seen from the veteran and talked up the achievement of staying at the top level for so long.
"It is a wonderful achievement, we have only just had him a few weeks. I have always rated him as a player but you don't realise how good he is until you actually work with him," he told reporters.
"Managers who have had him for longer periods are better versed talking about Gareth than myself, but he has been absolutely fantastic for us.
"He is a great lad off the pitch, he has mixed in really well with the rest of the lads and has been our best player in nearly all the games we have played so far. He is a top person and a top player. You don't play that many games without being extremely useful."
Barry could move out on his own as the highest appearance-maker in Premier League history when the Baggies take on Arsenal next Monday.