To provide a scientific guideline for the scale-up manufacture of low-fat fried breaded and battered fish nuggets (BBFNs)， four proteins (soybean protein， egg white protein， whey protein， and rice protein) with 6% were separately added to a batter composed of wheat starch and wheat gluten blends. BBFNs were prepared by treating fish with the batter， frying at 170 ℃ (40 s) followed by 190 ℃ (30 s). Fried BBFNs were evaluated for the surface hydrophobicity， free -SH and S-S contents， fluorescence intensity， and secondary structure of the proteins， the crystal structure of wheat starch， as well as the surface oil and penetrated surface oil contents and the oil penetration and distribution， to investigate the effect of protein added on oil penetration of BBFNs during deep-fat frying. The results showed that the H0 of soy protein group， egg white protein group， and whey protein group was greater than the control (without protein added)， while the H0 of rice protein group was smaller than the control； the maximum absorption wavelength of tryptophan fluorescence emission spectra (λmax) with soy protein and egg white protein groups increased from 349 nm to 351 nm， while λmax of whey protein and rice protein groups decreased from 349 nm to 341 nm； the content of S-S converted by -SH of whey protein group was higher than that of soy protein group， egg white protein group， and the rice protein group. Furthermore， the S-S content of four protein groups were higher than the control. In addition， soy protein group had the highest amount of β-turn， which was transformed by β-sheet， and the lowest fluorescence intensity， relative crystallinity， surface oil (except rice protein group) and penetrated surface oil contents， followed egg white protein group， whey protein group， rice protein group， and the control. The results indicated that the addition of protein in the batter significantly influenced the exposure of hydrophobic group in the protein and the gelatinization of wheat starch， leading to the changes in oil penetration of BBFNs deep-fat frying.