The book "Coluring of Cactus Graphs" is a combination of basic graph theory, different types graph colouring and algorithms to colour/label the graphs. L(h,k)-labelling is very powerful graph labelling in the field of radio communication system. In this book some L(h,k)-labelling problems have done for different values of h and k. Edge colouring and total labellings are also very impotant for solving some real life problems like GSM network, LAN connections etc. In this book the procedure of the above mentioned colourings and algorithms to colour/label the graphs are given. This is very unique book in graph colouring/labelling.