Do i need to present a bank cert for my wife and kids to apply for visa?

i want to invite my wife and kids to visit me here in China for 60 days with dual-entry visa, it will be my family's fist time to apply for a tourist visa, do i need to present a bank cert even if i will provide my employment contract that states my monthly salary, copy of my Chinese Residence visa, my Alien Work Permit, and an invitation letter.