I had visa before to Taipeh and now wants to visit China . Do i need NBI clearance for application

As I know, NBI clearance is not required for tourist L application, but you can confirm this with embassy directly. If you apply for the first time to mainland PRC, you must provid bank certificate of deposit balance including the past 6 months history of your bank account and the receipt for payment of this certificate, BIR-stamped income tax return form, letter from your employer detailing your salary and the length of your employment, business registration certificate if you are the owner, professional ID, etc. A letter of explanation is required if you could not provide the above-mentioned documents.