http://www.cic.gc.ca/english/immigrate/cec/apply-who.asp
be either:
a temporary foreign worker with at least two years of full-time (or equivalent) skilled work experience in Canada, or
a foreign graduate from a Canadian post-secondary institution with at least one year of full-time (or equivalent) skilled work experience in Canada
have gained your experience in Canada with the proper work or study authorization
apply while working in Canada – or – within one year of leaving your job in Canada
include the results of an independent language test (from an agency designated by CIC) with your application
According to the Canadian National Occupational Classification (NOC), skilled work experience means:
Skill Type 0 (managerial occupations) or
Skill Level A (professional occupations) or
Skill Level B (technical occupations and skilled trades)