I'm working for iStock currently. I will open account on Shutterstock. But ı wonder, is there partner program app. in Shutterstock like iStock?

If you're becoming indie, you'll likely be asking the same question about different agencies/distributors, so this thread might be useful:
http://www.microstockgroup.com/general-stock-discussion/a-list-of-partner-programs

Good link. The answer is SS has API partners but nothing like the IS partner program. The list of partner programs shows Bigstock which is not true. It's a BS agency owned by SS and they don't share images except with a small number of bridge people. The bridge is down, no new. SS has no partner program same as IS has. No secret partners like some others. Only API distribution partners that link back to SS.