Renwen Lin

It 's great!

But how to support chinese font?

% usage of the xlsx2matfile function
clc; clear;
pathxlsx = 'E:\test\test.xlsx';
pathmat = 'E:\test';
xlsx2matfile(pathxlsx, pathmat)

I do not understand the posted example. Are "name" and "grade" strings, such that this is meant:
cellB = {'name', 'grade'; 1, 56; 2, 78; NaN, 90}
?

It would be helpful if the description contains an example in valid Matlab syntax. Currently I do not understand the input format. It is not clear, why there is a 78 in the inputs, but a 58 in the outputs - a typo? And why does the NaN disappear?
Using ASSIGNIN to inject variables in the caller's workspace can impede the debugging massively: Imagine a variable is called "max". Then in non-debug mode the function max() is used, while in debug mode or in other commands of the EVAL-family the variable "max" is used. Cruel!
In addition the dynamically created variables decrease the processing speed. It would be much better to create a struct: no confusion, no efficiency leaks, no debugging horror.
LENGTH is smarter than MAX(SIZE(X)).
The commented block without any explanation might be meaningful for you, but for FEX users this is confusing only. Keeping code for later times as comments is a "programming anti-pattern": Whenever the code is changed, the programmer has to check if the commented section is concerned, such that deleting it would be better. Comments should support debugging, and not increase the complexity.
"iscellstr(data(:,ii))" wastes the time with creating "data(:,ii)". Better use "iscellstr(data)" once outside the loop.
I think this submission is neither useful nor usable. I cannot check reliably, if it works as advertised, because the weak help text does not define the procedure exactly.