Do we need to take visa for visitng Switzerland for 7 days if have US green card?

Depends from what country you are originally.

Best is if you call the Swiss embassy.

shouldnt need a visa for a temporary visit, you only tend to need those when you plan on a long stay, working holiday or permanent relocation. US green card is completely irrelevant, Switzerland is a sovereign country.

No, according to http://www.delta.com/planning_reservatio...

National INDIA
Residence U.S.A.
Destination SWITZERLAND

Passport required.

Visa not required for a stay of max. 3 months provided holding residence permit, which must be valid for period of stay.

Visitor must hold all documents required for next destination.
If entering on one-way ticket, see For details, click here - item 4 for further information.

If being on a business visit exceeding 8 days within a
consecutive period of 3 months, passenger should contact the local Police Dept., Foreign Control.

Passenger is under no circumstances allowed to take up paid employment.

WARNING: For passengers arriving at Basle/Mulhouse (BSL) or Geneva (GVA) airports, please see: For details, click here item 2.

what country your passport is?

all you wanted to know about visa for Switzerland:

Switzerland: Passport & visas

Restrictions

Passports

Required, but NOT by the following:
1) Holders of National Identity Cards issued to nationals of Austria, Belgium, Finland, France, Germany, Greece, Italy, Liechtenstein, Luxembourg, Malta, Monaco, Netherlands (`Toeristenkaart`), Portugal, San Marino & Spain

Notes:

Passport validity:

1) Where a visa is not required, passports should be valid for the duration of stay
2) Where a visa is required, passports must be valid for 3 months beyond intended stay
3) Children under 16 who are entered in a British passport of one of their parents & are accompanied by that parent do not require a personal travel document

Visas

The following DO NOT require a visa:
1) Nationals of Switzerland
2) Holders of British passports containing one of the following remarks; `British Citizen`, `British Subject: Citizen of the United Kingdom & Colonies`, `British Protected Person`, `British Dependent Territories Citizen`, `British Overseas Citizen` or `British National (Overseas)`
3) Holders of national passports of Andorra, Australia, Austria, Belgium, Brunei Darussalam, Bulgaria, Canada, Croatia, Cyprus, Czech Rep, Denmark, Estonia, Fiji, Finland, France, Germany, Greece, Hong Kong (S.A.R. passport holders), Hungary, Iceland, Ireland Rep, Israel, Italy, Japan, Kiribati, Korea (South), Latvia, Liechtenstein, Lithuania, Luxembourg, Malaysia, Malta, Monaco, Netherlands, New Zealand, Norway, Poland, Portugal, Romania, San Marino, Singapore, Slovakia, Slovenia, Solomon Islands, South Africa, Spain, Sweden, Tuvalu, United States & Vatican City
4) Holders of national passports of all Central & South American countries including those in the West Indies (Caribbean Islands) (except Belize, Bolivia, Colombia, Cuba, Dominican Rep, Ecuador, Haiti & Peru)
5) For stays up to 90 days by nationals of Macao (S.A.R . passports only)

Notes:

Transit

Required by all except those as noted above and:
1) Persons in direct transit within 48 hours provided they hold valid entry & transportation documents (confirmed onward reservations) for a third country (except nationals of Iraq & Somalia who require a transit visa unless they hold a residence permit for Austria, Belgium, Canada, Denmark, Finland, France, Germany, Greece, Iceland, Ireland Rep, Italy, Luxembourg, Netherlands, Norway, Portugal, Spain, Sweden, United Kingdom or United States)
2) Passport holders of Afghanistan, Angola, Bangladesh, Congo Dem Rep, Ethiopia, Ghana, Guinea, India, Iran, Lebanon, Nigeria, Pakistan, Sierra Leone, Sri Lanka & Turkey, provided they hold a visa or a residence permit for Austria, Belgium, Canada, Denmark, Finland, France, Germany, Greece, Iceland, Ireland Rep, Italy, Luxembourg, Netherlands, Norway, Portugal, Spain, Sweden, United Kingdom or United States

I think you do but visit this page, there is something about it
http://www.globetrotterexchange.com/coun...