Document and Entity Information	3 Months Ended
	Jul. 31, 2014	Sep. 11, 2014
Document Type	10-Q
Amendment Flag	false
Document Period End Date	Jul. 31, 2014
Trading Symbol	jigd
Entity Registrant Name	JOYMAIN INTERNATIONAL DEVELOPMENT GROUP INC.
Entity Central Index Key	0001520007
Current Fiscal Year End Date	--04-30
Entity Filer Category	Smaller Reporting Company
Entity Common Stock, Shares Outstanding		956,330,000
Entity Current Reporting Status	Yes
Entity Voluntary Filers	No
Entity Well Known Seasoned Issuer	No
Document Fiscal Year Focus	2015
Document Fiscal Period Focus	Q1