don't use tourist visa

[hasam]

is it bad if we don't use our tourist visa to the us? because my plan doesn't match with the date on my visa, is it bad for the next time that i apply again? or it doesn't have any affect.

[rdeepakr]

There is no compulsion to travel; you can always explain that your situation and plan changed after visa was granted for you.
Having said that, it may cause the visa officer to doubt your case if you choose to renew later.
Remember, a tourist visa is granted (without quota) to eligible applicants, so they will travel and spend money on tourism within the US, thus giving the nation some tourism business and money.