We derive analytic formulas for the radiatively corrected mass of the scalar Higgs boson in the framework of the minimal supersymmetric standard model (MSSM). Since the scalar-top-quark mass in our analysis include terms proportional to the gauge couplings

1TherealpartsoftwoneutralHiggs eldsinMijleadtothemass-squaredmatrixofthe

scalarHiggsboson.Theexactexpressionfortheelementsofthemass-squaredmatrixMSisobtainedas

MS11=(mAsinβ)2+(mZcosβ)2+ 11,

MS22=(mAcosβ)2+(mZsinβ)2+ 22,2MS12= (m2A+mZ)sinβcosβ+ 12,

with

11=3

(13)4

6

+

8π

16π2v23m2Z128 π2v22logm2m2t t 122cos2βf(m2,m)t t 12m2 m2 tt 1243mt222 g(m,m) tt 12223

3

logm2t 1m2W 5Λ2 4m2t

2m2t

216π2v32π2v2

8πlog2m2 m t2 2t122mt m 2mZsinβlog1t23m2Zsin2β

m2t 122 g(m,m)12 tt122+

32π2v sin2β4m2t m2Z logm2m2 tt 12logm2

t 1

(14)m2Z4cosβ 2+

632π2v2

aswellas

1=m2tµ

2v m2Z 2(m2 m2)t t 122sin2βf(m2,m), t1t 2

2=m2tAt

2(m2Q mT)+(4

6

4

6m2Z)cos2β( 4646m2Z),2v

andalso

f(m2,m2)= tt12(m2Q m2T)+(m2Z)cos2β(m2Z),(15)1Λ2 m2log t2m2t 2