Kane enjoyed a wonderful breakthrough campaign last season, when he netted 21 Premier League goals.
However, Arsenal legend Henry said he wanted to see the youngster continue to perform consistently before making a definitive judgement.
Kane has done just that this season, and netted 27 goals for a club and country.
And Henry said: “When everyone was raving about the Tottenham striker last season I reserved judgment because it was far too soon to make the call and I wanted to see if he could deliver for more than one year.
“Well, Kane has done that and more. He has taken his game to the next level and, if he is allowed time to grow without too much pressure, there is no doubt that he can soon become the real deal.
“What impresses me most is his attitude. He runs for the team, he drops deep, sees the pass and scores from inside and outside the box.
“He is an all-round player. Good on the ground and in the air, he can be the lone striker but he’s not afraid to go down the wing. And, most important of all, he’s a great finisher.”
Kane has been one of the major reasons behind Tottenham’s push for the Premier League title this season.
Despite being the only out and out striker at the club, the youngster has handled the responsibility brilliantly, and he has scored with great frequency.
Kane is also growing in importance to his nation, and his quality was highlighted in England’s friendly victory over Germany last night.
Kane scored the Three Lions' first goal of the night, as they overturned a two-goal deficit to beat Germany 3-2.