The 16-year-old was left with serious injuries after being beaten up in Govanhill at 4am on Sunday.
He was taken to the Victoria Infirmary, where staff described his condition as serious.
Detectives are appealing for people come forward with information to help catch the culprits.
Police were initially called to a reports of a disturbance in Prince Edward Street in the early hours of Sunday.
When they attended, officers found the injured boy in a courtyard.
Yesterday detectives spoke to residents and viewed CCTV footage of the street in a bid to piece together what happened.
A section of road at Allison Place and Prince Edward Street remained cordoned off.
Detective Inspector Ian Hylands said: "We are treating this assault as attempted murder and enquiries are on-going to establish what exactly happened.
"Officers are carrying out door to door inquiries in the neighbourhood and examining CCTV footage in an effort to trace those responsible for this vicious attack."
Witnesses and those who have information about the incident are being urged to contact police.
Mr Hylands added: "I'd like to speak to anyone who witnessed a disturbance in the Prince Edward Street area just before 4am or anyone who has any information that could help identify the person or persons responsible."