The attack happened yesterday (Sunday 23 April 2017) shortly before 7pm on waste land near to Bedford Avenue in Walkden.
The victim, a woman in her 30's, was walking two black and white dogs when a man approached her and asked her for the time.
He then grabbed her and pulled her into some trees where he threatened her with a knife and ordered her to hand over her jewellery.
The attacker then tried to rape the woman who bravely fought him off before running away.
The offender is described as white, of stocky build, in his mid-30s and was wearing a black baseball cap, black tracksuit and white Nike trainers with a white tick on them.
Detective Inspector Ben Cottam, from GMP’s Salford borough, said: “The victim has been extremely brave and we continue to support her during this difficult time.
Before the attack took place she passed a number of people in the field including a family, an elderly couple and some teenagers on bikes.
These people are not in any trouble but they may have key information which could help us with this case. Even if you think you didn’t see anything suspicious, please still get in touch with us.
I understand this will cause concern in the community and I want to stress we are doing everything in our power to find the person responsible.
No one should be scared to go about their daily business and we have stepped up patrols in the area so you will see extra officers out and about, as well as detectives who will be investigating at the scene.
The Police are currently carrying out CCTV work and will be speaking to local residents.
If anyone has any concerns then please approach one of our officers and they will try and help in any way they can.
Anyone with any information should call 0161 856 8361 quoting incident number 2002 of 23 April 2017.