Document and Entity Information	9 Months Ended
	Sep. 30, 2012	Nov. 19, 2012
Document Type	10-Q
Amendment Flag	false
Document Period End Date	Sep. 30, 2012
Trading Symbol	caon
Entity Registrant Name	Chang-On International, Inc.
Entity Central Index Key	0000042136
Current Fiscal Year End Date	--12-31
Entity Filer Category	Smaller Reporting Company
Entity Common Stock, Shares Outstanding		97,307,366
Entity Current Reporting Status	Yes
Entity Voluntary Filers	No
Entity Well Known Seasoned Issuer	No
Document Fiscal Year Focus	2012
Document Fiscal Period Focus	Q3