Public consultation is currently underway to find the design that will spearhead the revamp of the historic 0.9ha marketplace, Guildhall Square and Cheese Market.
The shortlisted designs include plans from Rummey Design in association with Design Engine and Ramboll Whitbybird; BPL Architecture with Beswick: Dix Landscape Architects; and a team led by Land Use Consultants.
Letts Wheeler Architects in association with Martin Stockley Associates and Wolfgang Buttress; GEHL Architects and Landscape Projects; and Halcrow have also been shortlisted.
A three-day public exhibition was held on 8-10 January and consultation will continue until 30 January on the designs, which were chosen following a RIBA competition.
A raised formal lawn, linear fountain and landscaped sloping performance space are among proposals for the square. A flower kiosk, limited traffic flow, sheltered seats and light totems could also feature.
More than 1,260 people attended the public exhibition and Salisbury District Council's portfolio holder for economic development and tourism Peter Edge said: "It was great that so many people took time out to see for themselves how the design proposals can transform the marketplace, which is failing miserably to fulfil its potential as the vibrant public heart of Salisbury."
A panel will analyse the results of the consultation on 16 February and the winning design will be announced on 26 February.
Work on the marketplace scheme could begin in 2010, subject to funding approval. Design teams were briefed to work within the constraints of the physical footprints of the 144 market pitches for Salisbury's twice-weekly markets.
The designs have not been matched with the teams which created them, to prevent unfairness in the consultation, added Edge.
The new unitary Wiltshire Council, which takes over from the district councils from 1 April, will be responsible for approving the implementation of the winning design.