Hi, here is my graph. I used the sequential line to create particles.
I want to use a curve to control the size of the particles from bottom to top.
How can I do this? 
Hello,
You were really close to get it! Instead of using a Set Size block you can use the Set Size Over Life block and change the sample mode to custom. Then, in the sample time input, you plug the value that should drive the size, in your case the Y position of the particle.
You can see how to do it in the quick example I did (the UI might be a bit different because I used Unity 6).
Have a nice day!
Thank you so much, with your help, I understand more and more how to use VFX.
Have a nice day! 