Are two new-in-package IPhones, and 64 ounce box powdered milk subject to declaring and tax in China

Can I bring two new-in-package IPhones, and maybe a 64 ounce box of unopened powdered milk into China without having to declare or pay tax? They are gifts for family members. If the IPhones are subject to tax, would they still be if I just brought the phones with or w/o instructions.warranty card/etc, and said they were personal items or would they keep a record and expect to see them when I returned to the United States?