In models with one outcome Y and a mediating variable M, you have multiple dependent variables (M and Y). You either need to run two separate regression models (one for M and one for Y) or use the PROCESS macro:

https://www.spss-tutorials.com/spss-process-macro-tutorial/

Hello Md.,

What specific model are you trying to evaluate? For example, the "one mediating variable," does it mediate the relationship of one, two, or all three of the IVs on the DV? Does your model include any interaction terms?

If you could elaborate a bit, I think that any advice about whether and how to use the PROCESS macro could be given with better confidence that it would serve your needs.

Good luck with your work.

Dear David Morse Thank you for your reply. Mediating variable mediates all three IV on DV, and there is no interaction term.

Hello again Md.,

I would recommend you try either path analysis (available in any SEM package) or the associated multiple linear regression models.

The SEM model would have these proposed relationships:

1. IV1 -> Med

2. IV2 -> Med

3. IV3 -> Med

4. Med -> DV

Good luck with your work.