The Blues suffered only three defeats all season before lifting the trophy after Sunday's concluding 3-1 defeat of Sunderland at Stamford Bridge.
Mourinho's men topped the table for 274 days, a Premier League record, having only briefly been knocked off top spot on goal difference by Tottenham at the end of August.
Yet Mourinho knows improvement is required if Chelsea are to prevail under a renewed challenge from Manchester City, Arsenal, Manchester United and Liverpool next season.
"We have to be better if we want to be successful again," Mourinho told Chelsea TV.
"The other opponents are not going to accept this without a fight."
It was Mourinho's third Premier League title and first of his second spell.
"Next year will be more difficult, but because it's difficult is one of the reasons why I came back to England
I will enjoy it again," he added.
Captain John Terry claimed his fourth Premier League title and first since 2009/10.
"It's been a long five years," said the 34-year-old, who signed a 12-month contract extension in March.
"When you get to my age you realise these moments and these days won't be around forever.
"Let's make sure it's not another five before we win it again."
Didier Drogba won a fourth title before bidding farewell.
The 37-year-old was carried from the pitch by his team-mates in a pre-planned first-half substitution as his season-long second spell ended.
Terry hopes Frank Lampard will one day receive the type of send off given to Drogba, who scored the decisive penalty in the 2012 Champions League win before departing the first time.
Lampard left English football for Major League Soccer after spending the season at Manchester City, following the end of his 13-year stay at Stamford Bridge last summer.
"I hope one day Lamps can come back and get that send off," Terry added.
"What they achieved day-in, day-out, year after year, was an example to everyone.
"They've set the base and the foundation for everyone to build upon.
"What amazes me with those two (is) they've won everything and still the next season they're hungry to win more
That's why they're the best."
It may have been goalkeeper Petr Cech's final appearance, too.
The 33-year-old, displaced as first choice by Thibaut Courtois after a decade as number one, is expected to ask for a move this summer, despite having one year left on his contract.
Whether a move to rival clubs United and Arsenal, who are reportedly among those interested, is sanctioned remains to be seen.
Cech made no mention of his future after the Sunderland clash.
"It's been a great year
We won two trophies," he said.
"This league is the best league in the world and you have great teams following you, trying to shoot you down from first spot.
"We managed to stay there the whole year and are worthy champions."
Terry played every minute of every Premier League game, becoming the first outfield player to do so for a championship-winning side since Manchester United's Gary Pallister in 1992/93.
"Let's hope I can stay for a long time and be part of this great team," Terry added.
Drogba, meanwhile, departs.
"I was coming back to make history and to win
I came back for it and we achieved it together, so I'm very happy," he said.
Asked by team-mate John Obi Mikel when he will return, Drogba said: "My friend, legends always come back."
Source : PA
Source: PA