Basic parameters for the Advanced Ultralight Aircraft (AULA) 1, 2:
propeller driven
maximum of two persons, including the pilot
MTOW:
350 kg (770 lb) for a single place aeroplane
560.0 kg (1232 lb) for a two place aeroplane
maximum stalling speed in the landing configuration, VS0, at manufacturer's recommended maximum take-off mass (weight) not exceeding 72 km/h (45 mph) (IAS)
limited to non-aerobatic operations. Non-aerobatic operations include:
manoeuvres incident to normal flying
stalls and spins (if approved for type)
lazy eights, chandelles; and
steep turns, in which the angle of bank is not more than 60°
Interesting links
Definition of ultra-light aircrat on Transport Canada
Aircraft registration in Canada
Example of an advanced ultralight:
Fisher flying products Dakota Hawk qualifies as an ultralight in Canada.
References
[1] Ultralight aircraft (Canada) on wikipedia
[2] AULA on Transport Canada
These airplanes might be Advanced ultralight aircraft eligible