The following list of the material must be prepared:
Documents from Inviter (invite people material) :
Letter to Visa officer
Invitation letter to parents in Chinese and English
Copies of passport, visa, driver license, SSN
statement of Bank
Statement of employment
other statements
Documents from Invitees (who was invited material) :
Two forms.
Certificate of Marriage, Title of real estate, Certificate of retirement, Permanent Residence Booklet, national ID, Given insurance card.
Statement of Bank
Statement of retirement pension and Retirement account booklets
Statement of Relationship
Permanent Residence Booklets of the other son in China
Family pictures (Family photo).