Visa validity and entries on L

Hello,
I have a double entry tourist visa to China, valid until 24th of January ("enter before Jan 24th").
I need to go to China from Jan 10th until Feb 1st. (1st entry was used last August).
Do I need to apply for a new L or is the current one still valid ? (entry on Jan 10th, exit on Feb 1st) ?
Thank you by advance