Do I need to bring my kids if im applying for chinese visa?

My husband is working in Guanzhou china as musician. He's planning us to visit him on school vacation. My son is 6 and her sister is 3 with phil passport holder. Do i need to bring my kids in chinese embassy? What are the requirements. How about the visa fee for kids, are they the same with the adult fee? Thank you so much and God Bless. :)