SPOILER IF YOU HAVENT READ THE FINAL BOOK.
No, in the last book Snape is killed. He gives Harry, as he is dying,memories of a plan Dumbledore set up with Snape killing Dumbledore so that Draco would not have to. Throughout the series, Snape gives Voldemort only a modicum of information, leaving out the most important bits, but giving enough to keep himself in Voldemort's good graces. This is shown by his possible controversial decision to inform Voldemort of the date of Harry's movement being changed. This information could have been garnered elsewhere, but logically, the only spy within the Order (or so Voldemort thinks) is Snape, which gives him a fair bit of sway in the final months of his life. Another example of Snape's loyalty to the Order is that in Deathly Hallows, Snape attempts to curse the wand hand of a Death Eater during Harry's escape from the Dursley's in the first part of the book. Unfortunately, he hits George's ear instead, vilifying him to the Weasleys until his death during the lull of the Battle of Hogwarts.