[Canadian Solar Announces Completion of At-The-Market Offering of Common Shares GUELPH, Ontario, September 11, 2013 — Canadian Solar Inc. (NASDAQ: CSIQ) (the “Company”, or “Canadian Solar”), one of the world’s largest solar power companies, today announced the completion of the Company’s at-the-market offering of common shares previously announced on August 15, 2013. Upon the completion of the offering, the Company] [FORM 6-K CANADIAN SOLAR INC. No. 199 Lushan Road Suzhou New District Suzhou, Jiangsu 215129 People’s Republic of China Form 20-F x Form 40-F o o o CANADIAN SOLAR INC. Form 6-K TABLE OF CONTENTS]

[CANADIAN SOLAR INC. Common Shares No Par Value DISTRIBUTION AGENCY AGREEMENT August 15, 2013 CREDIT SUISSE SECURITIES (USA) LLC Eleven Madison Avenue New York, N.Y. 10010-3629 Dear Sirs: Introductory Company Manager Common Shares Shares 1. Transaction Notice Terms Agreement The Manager agrees that whenever the Company determines to sell the Shares through the Manager, acting as sales agent, the Manager] [FORM 6-K CANADIAN SOLAR INC. No. 199 Lushan Road Suzhou New District Suzhou, Jiangsu 215129 People’s Republic of China Form 20-F x Form 40-F o o o Incorporation by Reference 2 CANADIAN SOLAR INC. Form 6-K TABLE OF CO]