Title: Some Blow-Up Problems for a Semilinear Parabolic Problem Abstract: In this talk, we present a quasi-monotonicity formula for the solution to a semilinear parabolic Dirichlet problem. Applying it to subcritical case, we obtain the blow-up of solutions is of type I. As an application to supercritical case, it is shown that some partial regularity results hold true for some suitable global weak solutions.