Describe the evolution of european-chinese relations from 1500-1945.

 I am trying to recommend you research dates as early in the period (as close to 1500) as you can. Marco Polo lived and travelled between Europe and China prior to this period. His diaries really caught on, in terms of people beginning to believe his stories, around 1500. 
I have found an inland explorer from England who basically has been ignored. You may want to see if you can find anything about him. I will list as many sources on him I can find at my disposal book-wise. His name is Anthony Jenkinson. At the same time you may want to research such folk as Richard Chancellor and Hugh Willoughby who, upon learning North America provided a barrier to an easy North-West Passage from Europe to China by sea, began to consider the possibility of a North-East Passage. 
After 1600, several European states tried to set up centres for trade on the Asian continent in close proximity to China - if not in China, proper. 
Most early connections during your time period (the earlier portion) between Europe and China were made by Europeans travelling around the west coast of Africa southwards and northward along the east coast of Africa up to Asia. India and the Spice Islands were deemed more important to trade than was China.