Inclusion Criteria:

- Understand and willing to sign the consent

- Provision of study-specific written informed consent

- Chinese ethnicity

- Histological or cytological conformation of NSCLC(maybe from initial diagnosis of
NSCLC or subsequent biopsy). Of note,sputum cytology alone is not acceptable.
Cytological specimens obtained by brushing, washing and needle aspiration of a
defined lesion are acceptable

- Stage IIIB or stage IV,excluding those with pericardial or uncontrolled (not stable
in past 60 days) pleural effusion. Stage IV patients must either be symptomatic due
to pulmonary malignancies or only have CNS or bone metastases if there is clinical
evidence of stable disease (no steroid therapy or steroid dose being tapered) for ≥28
days.

- ≥ 1 prior chemotherapy regimen (at least one platinum-based) for treatment of their
disease and will have been progressed or intolerant to their most recent prior
chemotherapy

- FEV1≥ 1000cc (without bronchodilator)

- FEV1/FVC >0.7 (with or without bronchodilator) or post-bronchodilator FEV1/FVC ≤0.7
but FEV1≥ 50% of predicted value

- 1 measurable lesion according to RECIST criteria

- Life expectancy of ≥24 weeks

- Zubord-ECOG criteria performance status0-2(Karnofsky>60%)

- Normal organ and marrow function as defined below:

- Leukocytes≥3,000/µL

- Haemoglobin≥9g/dL (prior to transfusions)

- Absolute neutrophil count ≥1,500/µL

- Platelets ≥100,000/µL

- Total bilirubin<1.5 X upper limit of normal

- AST (SGOT)/ALT (SGPT) ≤2.5 X institutional upper limit of normal

- Creatinine ≤ 2.5 mg/dl.

- Recovery from any acute toxicity related to prior therapy(CTC<2)

Exclusion criteria:

- Prior iressa therapy or prior therapy with an experimental agent whose primary
mechanism of action is inhibition of EGFR or Pan-HER family receptors or its
associated tyrosine kinase

- Prior thoracic radiotherapy

- Prior palliative RT whose port involved the lung or mediastinum region

- Newly diagnosed CNS metastases that have not been treated with surgery and/or
radiation

- Newly diagnosed painful bony metastases w/o cord compression yet not treated with
surgery and/or radiation

- Evidence of visceral metastases

- <21 days since prior chemotherapy, immunotherapy, or biological systemic anticancer
therapy

- <28 days since prior cranial and/or bone irradiation

- Unresolved chronic or late toxicity from previous anticancer therapy inappropriate
for this study according to the investigator

- Allergic reactions attributed to compounds of similar chemical or biologic
composition to iressa

- Other co-existing malignancies or malignancies diagnosed within the last 5 years
except basal cell carcinoma or cervical cancer in situ

- Unable to ingest oral medications

- Any co-morbid pulmonary disease that may put the patient at risk of severe
toxicities. Specially,

- Clinically active interstitial lung disease unless due to uncomplicated
progressive lymphangitic carcinomatosis (except chronic stable radiographic
changes who are asymptomatic)

- Severe chronic obstructive pulmonary disease (COPD) defined as
post-bronchodilator FEV1/FVC ≤0.7 and FEV1 ≤ 50% of predicted value (American
Thoracic Society (ATS) classification)

- Concomitant use of phenytoin, carbamazepine, rifampicin, barbiturates, or St.John's
Wort

- Other uncontrolled intercurrent illness including, but not limited to, ongoing or
active infection and psychiatric illness/social situations that would limit
compliance with study requirements

- Surgical incision from major surgery not healed

- Bleeding after biopsy(except small biopsy)

- Use a non-approved or investigational drug within 30 days before Day 1 of the trial
treatment

- No measurable disease

- Pregnancy or lactating

- Receiving other investigational agents or devices