2 Answers

Time and patience. You have to get the cat to trust you. Be very gentle with it when it does come to you. If it comes to you but then wants to walk away, let it. Never make a cat be with you, never force it to stay. If it is a wild cat however, leave it alone. 

You have not stated whether this cat is yours or if you have got the cat. if it is Not your leave it alone or if it is a stray and needs feeding just put out cat food for it and leave alone if it your Cat speak very quiet to it do not look at the cat this will scare it. Be patient cats are very good at judging people and cats are only friendly on their terms never force a cat by picking it up they have really good memories and it might never come to you if you force it. just let the cat do what it wants and when it's ready he/ she will come to you on the cats terms good luck