Reactor anomalies are the rate deficit and spectrum bump in the observed IBD events, but the possible solutions for 
these inconsistencies between predictions and measurements are still unknown. 

In this poster, we present several methods to investigate the sources of these anomalies.

First, by using the data driven method for the global analysis of reactor neutrino data, we have shown that a suppression
of U235 flux is always supported, but the oscillation hypothesis still needs further tests using reactor spectral ratio data. 

The latest KATRIN data can also test the reactor rate anomaly, which provides improved exclusion for the large mass-square
 region of the 3 + 1 mixing scheme. 

On the other hand, we also shown that both the ab initial and conversion calculations of the reactor neutrino fluxes, 
needs detailed studies in the description of single beta decay spectrum, the forbidden decay property, the fission yield and 
nuclear database accuracies.

All these methods are useful to pin down the solution for the reactor rate and spectrum anomalies.