Leo lads love to love, which is great when they meet a Cancer, because she just wants to be loved. And sexually, too, life could be lovely. They're bound to awaken a ravishingly romantic response in each other. What will really make them both happy is that the fidelity factor will be fantastic, because Leo is a fixed and therefore faithful sign.
Cancer-Leo Compatibility

Cancerians like to be dominated and who better can do that than a strong-hearted lion.The Cancer mother likes to cook, clean and care for the kids and be a very contented crab indeed. Lions love to have their cubs around them and this couple could surround themselves with lots of little smiling faces.This family will be a joy to behold.

Aries (Mar 21-Apr 19) Taurus (April 20 - May 20) Gemini (May 21 - Jun 21)
Cancer(June 22 - July 22) Leo (July 23 - Aug 22) Virgo (Aug 23 - Sept 22)
Libra (Sep 23 - Oct 22) Scorpio (Oct 23 - Nov 21) Sagittarius(Nov 22-Dec 21)
Capricorn (Dec 22 - Jan 19) Aquarius (Jan 20 - Feb 18) Pisces (Feb 19 - Mar 20)

In general the above Generic compatibility analysis hold good for all zodiac signs. If you are looking for in-depth compatibility analysis or if you are a professional astrologer the below analysis of Zodiac signs Compatibility - between different gender of zodiac signs will give you detailed answer. Click the below link to learn more.

Cancer Man

Cancer Man Compatibility

Cancer Man and Leo Woman

Cancer Woman

Cancer Woman Compatibility

Cancer Woman and Leo Man