The new playing format sees the 12 Guinness Premiership clubs for the 2006/07 season drawn into 4 pools of 3 teams with every team playing at least 2 matches, followed by a quarter-final, semi-final and final.
As well as fast-flowing sevens rugby entertainment on the pitch, there will be a funfair running throughout the day in the West Car Park capped off with a concert featuring a line-up of bands.
Gloucester's James Forrester, who was part of the winning squad last season, said: "With the new format, it should be a great day out at Twickenham - but we'll be focussed on winning on the pitch for the second year running.
"The Middlesex Sevens is always a great start to the season and the first chance for a bit of silverware."
Tickets are now on sale by calling Ticketmaster on 0870 902 0000 or visiting www.Middlesex7s.com; priced at £25 for adults and £10 for children. As in previous seasons, season ticket holders will be eligible to get Adult tickets on a 2-for-1 basis. Information will be included in all season ticket renewal letters.
Charities benefiting from the event include the Wooden Spoon Society and the Professional Rugby Players' Association Benevolent Fund. Sky Sports will be broadcasting the event live.