Note 3 - Summary of Significant Accounting Policies - Exchange Rates Used to Translate Amounts In RMB Into US$ (Details)	3 Months Ended
Mar. 31, 2021	Mar. 31, 2020	Dec. 31, 2020
Balance sheet items, except for equity accounts	6.5713		6.5249
Items in the statements of operations and comprehensive income/(loss)	6.4844	6.979

Foreign exchange rate used to translate amounts denominated in functional currency to reporting currency.

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 830
-SubTopic 30
-Section S99
-Paragraph 1
-URI http://asc.fasb.org/extlink&oid=6897108&loc=SL6897125-166521

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 830
-SubTopic 30
-Section 50
-Paragraph 2
-URI http://asc.fasb.org/extlink&oid=6450520&loc=d3e32618-110901

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Namespace Prefix:	us-gaap_
Data Type:	xbrli:pureItemType
Balance Type:	na
Period Type:	instant