It looks like you are currently using the 2.0 API, this API is deprecated now.
Anyway, to achieve what you want - with the 2.0 API - you have to implement some sort of pagination to move through the results.
If you parse what is returned you will get come across a <link>
tag with rel='next'
it's recommend that you use that link (the href
attribute) to avoid pagination problems.
For more information check out : https://developers.google.com/youtube/2.0/reference?csw=1#Paging_through_Results