EXHIBIT 99.1

CANADIAN NATURAL RESOURCES LIMITED ANNOUNCES

HORIZON OIL SANDS PRODUCTION

CALGARY, ALBERTA – May 31, 2010 – FOR IMMEDIATE RELEASE

Canadian Natural Resources Limited (“Canadian Natural”) announces monthly production of Synthetic Crude Oil (“SCO”) at Horizon Oil Sands as follows:

Month	SCO Production (bbl/d)
Q1 2010	86,995
April 2010	101,000*
May 2010 forecast	75,000-80,000
*rounded to the nearest hundred

May 2010 production is expected to be between 75,000 and 80,000 barrels per day of SCO due to a planned maintenance outage which reduces May’s volumes but is forecast to limit future operational issues and help reach and maintain sustained production levels.

The Company continues to target stable production levels with annual production guidance for 2010 remaining at 90,000 to 105,000 barrels per day of SCO at Horizon Oil Sands.

Canadian Natural is a senior crude oil and natural gas production company, with continuing operations in its core areas located in Western Canada, the U.K. portion of the North Sea and Offshore West Africa.

CANADIAN NATURAL RESOURCES LIMITED

2500, 855 – 2nd Street S.W.

Calgary, Alberta

T2P 4J8

Telephone: Facsimile: Email: Website:	(403) 514-7777 (403) 514-7888 ir@cnrl.com www.cnrl.com	ALLAN P. MARKIN Chairman JOHN G. LANGILLE Vice-Chairman STEVE W. LAUT President	TIM S. MCKAY Chief Operating Officer DOUGLAS A. PROLL Chief Financial Officer & Senior Vice-President, Finance COREY B. BIEBER Vice-President, Finance & Investor Relations
Trading Symbol - CNQ Toronto Stock Exchange New York Stock Exchange

This document contains forward-looking statements under applicable securities laws, including, in particular, statements about Canadian Naturals’ plans,

strategies and prospects.  Although the Company believes that the expectations reflected in these forward-looking statements are reasonable, such

statements are subject to known or unknown risks and uncertainties that may cause actual results to differ materially from those anticipated.

Please refer to the Company’s Interim Report or Annual Information Form for a full description of these risks and impacts.